549 F.3d 685 (2008)

Stanley BOIM, individually and as administrator of the Estate of David Boim, deceased; and Joyce Boim, Plaintiffs-Appellees,
v.
HOLY LAND FOUNDATION FOR RELIEF AND DEVELOPMENT, et al., Defendants-Appellants.

Nos. 05-1815, 05-1816, 05-1821, 05-1822.

United States Court of Appeals, Seventh Circuit.

Argued September 10, 2008. Decided December 3, 2008.

*687 Stephen J. Landes (argued), Wildman, Harrold, Allen & Dixon, Chicago, IL, Nathan Lewin (argued), Lewin & Lewin, Washington, DC, for Plaintiffs-Appellees.

John W. Boyd (argued), Freedman, Boyd, Daniels, Peifer, Hollander, Guttman & Goldbe, Albuquerque, NM, for Defendant-Appellant Holy Land Foundation for Relief and Development in No. 05-1815.

Matthew J. Piers (argued), Mary M. Rowland, Hughes Socol Piers Resnick & Dym, for Defendant-Appellant Mohammad Abdul Hamid Khalil Salah in No. 05-1816.

John M. Beal, Chicago, IL, for Defendant-Appellant Quaranic Literacy Institute in No. 05-1821.

James R. Fennerty, Brendan Shiller, Chicago, IL, for Defendant-Appellant American Muslim Society in No. 05-1822.

Joseph A. Morris, Morris & De La Rosa, Chicago, IL, for Jewish Community Relations Council of the Jewish United Fund of Metropolitan Chicago.

Daniel Elbaum, Anti-Defamation League, Jonathan K. Baum, Katten Muchin Rosenman, Chicago, IL, for Anti-Defamation League.

Thomas P. Walsh, Office of United States Attorney, Chicago, IL for U.S.

Leon F. DeJulius, Jr., Jones Day, Pittsburgh, PA, for OMB Watch.

Andrea Bierstein, Hanly Conroy Bierstein Sheridan Fisher & Hayes, New York, NY, for 9/11 Families United to Bankrupt Terrorism.

David Yerushalmi, Washington, DC, Center for Security Policy.

Richard A. Samp, Washington Legal Foundation, Washington, DC, for Washington Legal Foundation, Jewish Institute for National Security Affairs and Allied Educational Foundation.

Before EASTERBROOK, Chief Judge, and POSNER, FLAUM, KANNE, ROVNER, WOOD, EVANS, WILLIAMS, SYKES, and TINDER, Circuit Judges.

POSNER, Circuit Judge.

In 1996 David Boim, a Jewish teenager who was both an Israeli citizen and an American citizen, living in Israel, was shot to death by two men at a bus stop near Jerusalem. His parents filed this suit four years later, alleging that his killers had been Hamas gunmen and naming as defendants Muhammad Salah plus three organizations: the Holy Land Foundation for Relief and Development, the American Muslim Society, and the Quranic Literacy Institute. (A fourth, the Islamic Association *688 of Palestine-National, appears to be either an alter ego of the American Muslim Society or just an alternative name for it, and need not be discussed separately. There are other defendants as well but they are not involved in the appeals.) The complaint accused the defendants of having provided financial support to Hamas before David Boim's death and by doing so of having violated 18 U.S.C. § 2333(a), which provides that "any national of the United States injured in his or her person, property, or business by reason of an act of international terrorism, or his or her estate, survivors, or heirs, may sue therefor in any appropriate district court of the United States and shall recover threefold the damages he or she sustains and the cost of the suit, including attorney's fees."

The district court denied the defendants' motion to dismiss the complaint for failure to state a claim, 127 F.Supp.2d 1002 (N.D.Ill.2001); the defendants had argued that providing financial assistance to a terrorist group is not an act of international terrorism and therefore is not within the scope of section 2333. We authorized an interlocutory appeal, 28 U.S.C. § 1292(b), and the panel that heard the appeal affirmed the district court. Boim v. Quranic Literacy Institute, 291 F.3d 1000 (7th Cir.2002). The case then resumed in that court. The court granted summary judgment in favor of the plaintiffs with respect to the liability of the three defendants other than the Quranic Literacy Institute. 340 F.Supp.2d 885 (N.D.Ill.2004). A jury was convened and, after a trial lasting a week, found the Institute — which having filed a statement of "nonparticipation" attended but did not participate in the trial — liable. The jury then assessed damages of $52 million against all the defendants (including the ones not before us) jointly and severally. The amount was then trebled and attorneys' fees added.

These defendants again appealed, this time from a final judgment. The panel vacated the judgment and directed the district court to redetermine liability. 511 F.3d 707 (7th Cir.2007). Judge Evans agreed with the reversal as to the Holy Land Foundation but otherwise dissented.

The plaintiffs petitioned for rehearing en banc, and the full court granted the petition, primarily to consider the elements of a suit under 18 U.S.C. § 2333 against financial supporters of terrorism. The parties have filed supplemental briefs. A number of amici curiae have weighed in as well, including the Department of Justice, which has taken the side of the plaintiffs.

The first panel opinion rejected the argument that the statute does not impose liability on donors to groups that sponsor or engage in terrorism. The supplemental briefs do not revisit the issue, and at oral argument counsel for Salah and the Holy Land Foundation disclaimed reliance on their former position concerning the liability of donors. But in a letter to the court after oral argument, Salah's counsel indicated that the disclaimer had been based solely on a belief that the doctrine of law of the case foreclosed any further consideration of the statutory issue in this court. That was a mistake. The full court can revisit any ruling by a panel. All arguments that the defendants have presented in their appeals are open today — and will be open in the Supreme Court. It is better to decide the question than to leave it hanging; why bother to address the elements of a legal claim that may not exist? Before deciding what a plaintiff must prove in order to recover from a donor under section 2333, we should decide whether the statute applies. United States National Bank of Oregon v. Insurance Agents of America, Inc., 508 U.S. *689 439, 445-48, 113 S.Ct. 2173, 124 L.Ed.2d 402 (1993).

Section 2333 does not say that someone who assists in an act of international terrorism is liable; that is, it does not mention "secondary" liability, the kind that 18 U.S.C. § 2 creates by imposing criminal liability on "whoever commits an offense against the United States or aids, abets, counsels, commands, induces or procures its commission," or "willfully causes an act to be done which if directly performed by him or another would be an offense against the United States." See also 18 U.S.C. § 3 (accessory after the fact). The Supreme Court in Central Bank of Denver, N.A. v. First Interstate Bank of Denver, N.A., 511 U.S. 164, 114 S.Ct. 1439, 128 L.Ed.2d 119 (1994), held that section 10(b) of the Securities and Exchange Act of 1934, which prohibits securities fraud, does not reach aiding and abetting because it makes no reference to secondary liability, the kind of liability that statutes such as 18 U.S.C. §§ 2 and 3 create in criminal cases. The Court discussed the securities laws at length, but nothing in its holding turns on particular features of those laws.

So statutory silence on the subject of secondary liability means there is none; and section 2333(a) authorizes awards of damages to private parties but does not mention aiders and abettors or other secondary actors. Nevertheless the first panel opinion concluded that section 2333 does create secondary liability. It distinguished Central Bank of Denver as having involved an implied private right of action (for it was a private suit, yet section 10(b) does not purport to authorize such suits), while section 2333(a) expressly creates a private right. But as the dissenting Justices in Central Bank of Denver had pointed out, the majority's holding was not limited to private actions. 511 U.S. at 200, 114 S.Ct. 1439. It encompassed suits by the SEC, which section 10(b) authorizes expressly.

Congress agreed with this understanding of Central Bank of Denver, for the next year it enacted 15 U.S.C. § 78t(e) to allow the SEC in section 10(b) suits to obtain relief against aiders, abettors, and others who facilitate primary violations. Stoneridge Investment Partners, LLC v. Scientific-Atlanta, Inc., ___ U.S. ___, 128 S.Ct. 761, 771-72, 169 L.Ed.2d 627 (2008). The enactment of section 78t(e) would have been pointless had Central Bank of Denver allowed secondary liability to be imposed in suits, such as suits by the SEC under section 10(b), that the statute expressly authorizes. Years later, reaffirming Central Bank of Denver, the Supreme Court repeated that the earlier decision had not been limited to private suits under section 10(b). Stoneridge Investment Partners, LLC v. Scientific-Atlanta, Inc., supra, 128 S.Ct. at 768-69.

The first panel opinion relied on Harris Trust & Savings Bank v. Salomon Smith Barney, Inc., 530 U.S. 238, 120 S.Ct. 2180, 147 L.Ed.2d 187 (2000), an ERISA case involving an application of trust law. Trust law permits trust beneficiaries to maintain actions against third parties who have received trust assets improperly. ERISA not only does not upset this principle of trust law; it authorizes the Secretary of Labor to penalize third parties who "knowing[ly] participat[e]" in a fiduciary's misconduct. 29 U.S.C. §§ 1106(a), 1132(l)(1)(B). Harris Trust did not cite Central Bank of Denver and did not purport to limit its holding. Stoneridge, decided eight years after Harris Trust, also did not treat Harris Trust as circumscribing Central Bank of Denver — it did not even cite Harris Trust.

To read secondary liability into section 2333(a), moreover, would enlarge the *690 federal courts' extraterritorial jurisdiction. The defendants are accused of promoting terrorist activities abroad. Congress has the power to impose liability for acts that occur abroad but have effects within the United States, F. Hoffmann-La Roche Ltd. v. Empagran S.A., 542 U.S. 155, 165, 124 S.Ct. 2359, 159 L.Ed.2d 226 (2004), but it must make the extraterritorial scope of a statute clear. Small v. United States, 544 U.S. 385, 388-89, 125 S.Ct. 1752, 161 L.Ed.2d 651 (2005); EEOC v. Arabian American Oil Co., 499 U.S. 244, 248, 111 S.Ct. 1227, 113 L.Ed.2d 274 (1991).

The first panel opinion discussed approvingly an alternative and more promising ground for bringing donors to terrorist organizations within the grasp of section 2333. The ground involves a chain of explicit statutory incorporations by reference. The first link in the chain is the statutory definition of "international terrorism" as "activities that ... involve violent acts or acts dangerous to human life that are a violation of the criminal laws of the United States," that "appear to be intended ... to intimidate or coerce a civilian population" or "affect the conduct of a government by ... assassination," and that "transcend national boundaries in terms of the means by which they are accomplished" or "the persons they appear intended to intimidate or coerce." 18 U.S.C. § 2331(1). Section 2331 was enacted as part of the Federal Courts Administration Act of 1992, Pub.L. No. 102-572, § 1003(a)(3), 106 Stat. 4506, 4521. Section 2333 (having been originally enacted in 1990 and repealed for a technical reason the next year) was reenacted in 1992 as part of that same Federal Courts Administration Act. So the two sections are part of the same statutory scheme and are to be read together. Nicholas J. Perry, "The Numerous Federal Legal Definitions of Terrorism: The Problem of Too Many Grails," 30 J. Legis. 249, 257 (2004).

Section 2331(1)'s definition of international terrorism (amended in 2001 by the PATRIOT Act, Pub.L. No. 107-56, § 802(a)(1), 115 Stat. 272, 376, but in respects irrelevant to this case) includes not only violent acts but also "acts dangerous to human life that are a violation of the criminal laws of the United States." Giving money to Hamas, like giving a loaded gun to a child (which also is not a violent act), is an "act dangerous to human life." And it violates a federal criminal statute enacted in 1994 and thus before the murder of David Boim — 18 U.S.C. § 2339A(a), which provides that "whoever provides material support or resources ..., knowing or intending that they are to be used in preparation for, or in carrying out, a violation of [18 U.S.C. § 2332]," shall be guilty of a federal crime. So we go to 18 U.S.C. § 2332 and discover that it criminalizes the killing (whether classified as homicide, voluntary manslaughter, or involuntary manslaughter), conspiring to kill, or inflicting bodily injury on, any American citizen outside the United States.

By this chain of incorporations by reference (section 2333(a) to section 2331(1) to section 2339A to section 2332), we see that a donation to a terrorist group that targets Americans outside the United States may violate section 2333. Which makes good sense as a counterterrorism measure. Damages are a less effective remedy against terrorists and their organizations than against their financial angels. Terrorist organizations have been sued under section 2333, e.g., Ungar v. Palestine Liberation Organization, 402 F.3d 274 (1st Cir.2005); Biton v. Palestinian Interim Self-Government Authority, 252 F.R.D. 1 (D.D.C.2008); Knox v. Palestine Liberation Organization, 248 F.R.D. 420 (S.D.N.Y.2008), but to collect a damages *691 judgment against such an organization, let alone a judgment against the terrorists themselves (if they can even be identified and thus sued), is, as the first panel opinion pointed out, 291 F.3d at 1021, well-nigh impossible. These are foreign organizations and individuals, operating abroad and often covertly, and they are often impecunious as well. So difficult is it to obtain monetary relief against covert foreign organizations like these that Congress has taken to passing legislation authorizing the payment of judgments against them from U.S. Treasury funds. E.g., Victims of Trafficking and Violence Protection Act of 2000, Pub.L. No. 106-386, § 2002, 114 Stat. 1464. But that can have no deterrent or incapacitative effect, whereas suits against financiers of terrorism can cut the terrorists' lifeline.

And whether it makes good sense or not, the imposition of civil liability through the chain of incorporations is compelled by the statutory texts — as the panel determined in its first opinion. 291 F.3d at 1012-16. But in addition the panel placed a common law aiding and abetting gloss on section 2333. The panel was worried about a timing problem: section 2339A was not passed until 1994, and the defendants' contributions to Hamas began earlier. But that is not a serious problem on the view we take of the standard for proving causation under section 2333; we shall see that the fact of contributing to a terrorist organization rather than the amount of the contribution is the keystone of liability.

Only because this is a very old case — David Boim was killed 12 years ago — does the 1994 effective date of section 2339A, two years before his killing, present an obstacle to liability, though only with respect to Salah and possibly the Holy Land Foundation (but we are vacating the judgment against the latter anyway, as we shall explain). For there is no doubt that the other defendants made contributions after section 2339A's effective date. Salah, however, having been arrested by Israeli authorities in 1993 and not released until 1997, did not render material support to Hamas between the effective date of section 2339A and Boim's killing, so the judgment against him must be reversed. Few future cases will be affected by the timing issue, because few such cases will involve donations that were made after section 2333 was enacted in 1990 or re-enacted in 1992 but that ceased before 1994.

In addition to providing material support after the effective date of section 2339A, a donor to terrorism, to be liable under section 2333, must have known that the money would be used in preparation for or in carrying out the killing or attempted killing of, conspiring to kill, or inflicting bodily injury on, an American citizen abroad. We know that Hamas kills Israeli Jews; and Boim was an Israeli citizen, Jewish, living in Israel, and therefore a natural target for Hamas. But we must consider the knowledge that the donor to a terrorist organization must be shown to possess in order to be liable under section 2333 and the proof required to link the donor's act to the injury sustained by the victim. The parties have discussed both issues mainly under the rubrics of "conspiracy" and "aiding and abetting." Although those labels are significant primarily in criminal cases, they can be used to establish tort liability, see, e.g., Halberstam v. Welch, 705 F.2d 472 (D.C.Cir.1983); Restatement (Second) of Torts §§ 876(a), (b) (1979), and there is no impropriety in discussing them in reference to the liability of donors to terrorism under section 2333 just because that liability is primary. Primary liability in the form of material support to terrorism has the character of secondary liability. *692 Through a chain of incorporations by reference, Congress has expressly imposed liability on a class of aiders and abettors.

When a federal tort statute does not create secondary liability, so that the only defendants are primary violators, the ordinary tort requirements relating to fault, state of mind, causation, and foreseeability must be satisfied for the plaintiff to obtain a judgment. See, e.g., Bridge v. Phoenix Bond & Indemnity Co., ___ U.S. ___, 128 S.Ct. 2131, 2141-44, 170 L.Ed.2d 1012 (2008); Stoneridge Investment Partners, LLC v. Scientific-Atlanta, Inc., supra, 128 S.Ct. at 769; Holmes v. Securities Investor Protection Corp., 503 U.S. 258, 268-69, 112 S.Ct. 1311, 117 L.Ed.2d 532 (1992); Associated General Contractors of California, Inc. v. California State Council of Carpenters, 459 U.S. 519, 103 S.Ct. 897, 74 L.Ed.2d 723 (1983). But when the primary liability is that of someone who aids someone else, so that functionally the primary violator is an aider and abettor or other secondary actor, a different set of principles comes into play. Those principles are most fully developed in the criminal context, but we must be careful in borrowing from criminal law because the state-of-mind and causation requirements in criminal cases often differ from those in civil cases. For example, because the criminal law focuses on the dangerousness of a defendant's conduct, the requirement of proving that a criminal act caused an injury is often attenuated and sometimes dispensed with altogether, as in the statutes that impose criminal liability on providers of material support to terrorism (18 U.S.C. §§ 2339A, B, and C), which do not require proof that the material support resulted in an actual terrorist act, or that punish an attempt (e.g., 18 U.S.C. § 1113) that the intended victim may not even have noticed, so that there is no injury. The law of attempt has no counterpart in tort law, United States v. Gladish, 536 F.3d 646, 648 (7th Cir.2008), because there is no tort without an injury. E.g., Rozenfeld v. Medical Protective Co., 73 F.3d 154, 155-56 (7th Cir.1996); Winskunas v. Birnbaum, 23 F.3d 1264, 1267 (7th Cir.1994).

So prudence counsels us not to halt our analysis with aiding and abetting but to go on and analyze the tort liability of providers of material support to terrorism under general principles of tort law. We begin by noting that knowledge and intent have lesser roles in tort law than in criminal law. A volitional act that causes an injury gives rise to tort liability for negligence if the injurer failed to exercise due care, period. But more is required in the case of intentional torts, and we can assume that since section 2333 provides for an automatic trebling of damages it would require proof of intentional misconduct even if the plaintiffs in this case did not have to satisfy the state-of-mind requirements of sections 2339A and 2332 (but they do).

Punitive damages are rarely if ever imposed unless the defendant is found to have engaged in deliberate wrongdoing. "Something more than the mere commission of a tort is always required for punitive damages. There must be circumstances of aggravation or outrage, such as spite or `malice,' or a fraudulent or evil motive on the part of the defendant, or such a conscious and deliberate disregard of the interests of others that the conduct may be called wilful or wanton." W. Page Keeton et al., Prosser and Keeton on the Law of Torts § 2, pp. 9-10 (5th ed.1984); see, e.g., Molzof v. United States, 502 U.S. 301, 305-07, 112 S.Ct. 711, 116 L.Ed.2d 731 (1992); Kemezy v. Peters, 79 F.3d 33, 35 (7th Cir.1996). Treble damages too, not being compensatory, tend to have a punitive aim. "The very idea of treble damages reveals an intent to punish past, and to deter future, unlawful conduct." Texas *693 Industries, Inc. v. Radcliff Materials, Inc., 451 U.S. 630, 639, 101 S.Ct. 2061, 68 L.Ed.2d 500 (1981); see also Vermont Agency of Natural Resources v. United States ex rel. Stevens, 529 U.S. 765, 784-86, 120 S.Ct. 1858, 146 L.Ed.2d 836 (2000); Zelinski v. Columbia 300, Inc., 335 F.3d 633, 642 (7th Cir.2003); Gorenstein Enterprises, Inc. v. Quality Care-USA, Inc., 874 F.2d 431, 435-36 (7th Cir.1989); United States v. Mackby, 261 F.3d 821, 830-31 (9th Cir.2001).

To give money to an organization that commits terrorist acts is not intentional misconduct unless one either knows that the organization engages in such acts or is deliberately indifferent to whether it does or not, meaning that one knows there is a substantial probability that the organization engages in terrorism but one does not care. "When the facts known to a person place him on notice of a risk, he cannot ignore the facts and plead ignorance of the risk." Makor Issues & Rights, Ltd. v. Tellabs Inc., 513 F.3d 702, 704 (7th Cir. 2008). That is recklessness and equivalent to recklessness is "wantonness," which "has been defined as the conscious doing of some act or omission of some duty under knowledge of existing conditions and conscious that from the doing of such act or omission of such duty injury will likely or probably result." Graves v. Wildsmith, 278 Ala. 228, 177 So.2d 448, 451 (1965); see also Landers v. School District No. 203, O'Fallon, 66 Ill.App.3d 78, 22 Ill.Dec. 837, 383 N.E.2d 645 (1978). "[I]n one case we read that `willful and wanton misconduct approaches the degree of moral blame attached to intentional harm, since the defendant deliberately inflicts a highly unreasonable risk of harm upon others in conscious disregard of it.' Similarly, [another case] defines `willful and wanton' as exhibiting `an utter indifference to or conscious disregard for' safety." Fagocki v. Algonquin/Lake-in-the-Hills Fire Protection District, 496 F.3d 623, 627 (7th Cir. 2007) (citations omitted).

So it would not be enough to impose liability on a donor for violating section 2333, even if there were no state-of-mind requirements in sections 2339A and 2332, that the average person or a reasonable person would realize that the organization he was supporting was a terrorist organization, if the actual defendant did not realize it. That would just be negligence. But if you give a gun you know is loaded to a child, you know you are creating a substantial risk of injury and therefore your doing so is reckless and if the child shoots someone you will be liable to the victim. See Pratt v. Martineau, 69 Mass.App.Ct. 670, 870 N.E.2d 1122 (2007); Bowen v. Florida, 791 So.2d 44, 48-49 (Fla.App. 2001). That case should be distinguished from one in which the gun is given to an adult without adequately explaining the dangers — a case of negligent entrustment. To give a small child a loaded gun would be a case of criminal recklessness and therefore satisfy the state of mind requirement for liability under section 2333 and the statutes that it incorporates by reference. For the giver would know he was doing something extremely dangerous and without justification. "If the actor knows that the consequences are certain, or substantially certain, to result from his act, and still goes ahead, he is treated by the law as if he had in fact desired to produce the result." Restatement, supra, § 8A, comment b. That you did not desire the child to shoot anyone would thus be irrelevant, not only in a tort case, see EEOC v. Illinois, 69 F.3d 167, 170 (7th Cir.1995), but in a criminal case. United States v. Fountain, 768 F.2d 790, 798 (7th Cir.1985); cf. United States v. Ortega, 44 F.3d 505, 508 (7th Cir.1995).

A knowing donor to Hamas — that is, a donor who knew the aims and activities of *694 the organization — would know that Hamas was gunning for Israelis (unlike some other terrorist groups, Hamas's terrorism is limited to the territory of Palestine, including Israel; see Council on Foreign Relations, "Hamas," www.cfr.org/publication/ 8968/, visited Nov. 16, 2008), that Americans are frequent visitors to and sojourners in Israel, that many U.S. citizens live in Israel (American Citizens Abroad, an advocacy group for expatriates, reports on the basis of State Department data that in 1999 there were about 184,000 American citizens living in Israel, accounting for about 3.1 percent of the country's population, www.aca.ch/amabroad.pdf, visited Nov. 16, 2008), and that donations to Hamas, by augmenting Hamas's resources, would enable Hamas to kill or wound, or try to kill, or conspire to kill more people in Israel. And given such foreseeable consequences, such donations would "appear to be intended ... to intimidate or coerce a civilian population" or to "affect the conduct of a government by ... assassination," as required by section 2331(1) in order to distinguish terrorist acts from other violent crimes, though it is not a state-of-mind requirement; it is a matter of external appearance rather than subjective intent, which is internal to the intender.

It is true that "the word `recklessness' in law covers a spectrum of meaning, ranging from gross negligence in an accident case to the conduct of a robber in shooting at a pursuing policeman without aiming carefully." Wright v. United States, 809 F.2d 425, 427 (7th Cir.1987). In tort law it sometimes connotes merely gross negligence and at other times requires only that the defendant have acted in the face of an unreasonable risk that he should have been aware of even if he wasn't. But when, as in the passages we have quoted both from judicial opinions and from the Restatement, recklessness entails actual knowledge of the risk, the tort concept merges with the criminal concept, which likewise "generally permits a finding of recklessness only when a person disregards a risk of harm of which he is aware." Farmer v. Brennan, 511 U.S. 825, 837, 114 S.Ct. 1970, 128 L.Ed.2d 811 (1994); see also Desnick v. American Broadcasting Cos., 233 F.3d 514, 517-518 (7th Cir.2000); American Law Institute, Model Penal Code § 2.02(2)(c) (1962) (defining recklessness as "consciously disregard[ing] a substantial and unjustifiable risk that the material element exists or will result from his conduct").

Critically, the criminal (like the tort) concept of recklessness is more concerned with the nature and knowledge of the risk that the defendant creates than with its magnitude. The Court in Farmer v. Brennan spoke of an "excessive" risk, a "significant" risk, a "substantial" risk, and an "intolerable" risk, 511 U.S. at 837-38, 842-43, 846, 114 S.Ct. 1970, the Model Penal Code of a "substantial and unjustifiable" risk, and the Restatement of an "unreasonable" risk, Restatement, supra, § 500, rather than assigning a minimum probability to the risk. These are relative terms; what is excessive, intolerable, etc., depends on the nature of the defendant's conduct. Ordinarily, it is true, the risk is great in a probabilistic sense; for the greater it is, the more likely it is to materialize and so give rise to a lawsuit or a prosecution and thus be mentioned in a judicial opinion. The greater the risk, moreover, the more obvious it will be to the risk taker, enabling the trier of fact to infer the risk taker's knowledge of the risk with greater confidence, see, e.g., Farmer v. Brennan, supra, 511 U.S. at 842, 114 S.Ct. 1970; Duckworth v. Franzen, 780 F.2d 645, 652 (7th Cir.1985), though, as the Farmer decision emphasizes, subject to rebuttal. 511 U.S. at 837-42, 114 S.Ct. 1970.

*695 But probability isn't everything. The risk that one of the workers on a project to build a bridge or a skyscraper will be killed may be greater than the risk that a driver will be killed by someone who flings rocks from an overpass at the cars traveling on the highway beneath. But only the second risk, though smaller, is deemed excessive and therefore reckless. McNabb v. State, 887 So.2d 929, 974-75 (Ala.Crim. App.2001). (The first risk might not even be negligent.) As we explained in United States v. Boyd, 475 F.3d 875, 877 (7th Cir.2007) (emphasis added), "firing multiple shots from a powerful gun ... in the downtown of a large city at a time when pedestrians ... are known to be in the vicinity creates a risk of harm that, while not large in probabilistic terms, is `substantial' relative to the gratuitousness of the defendant's actions.... An activity is reckless when the potential harm that it creates ... is wildly disproportionate to any benefits that the activity might be expected to confer.... The emotional gratification that defendant Boyd derived from shooting into the night, though perhaps great, is not the kind of benefit that has weight in the scales when on the other side is danger to life and limb, even if the danger is limited, as it was here." Lennon v. Metropolitan Life Ins. Co., 504 F.3d 617, 623 (6th Cir.2007), says that the risk must be "weighed against the lack of social utility of the activity" in adjudging its reasonableness. See also Orban v. Vaughn, 123 F.3d 727, 733 (3d Cir.1997).

So if you give a person rocks who has told you he would like to kill drivers by dropping them on cars from an overpass, and he succeeds against the odds in killing someone by this means, you are guilty of providing material support to a murderer, or equivalently of aiding and abetting — for remember that when the primary violator of a statute is someone who provides assistance to another he is functionally an aider and abettor. The mental element required to fix liability on a donor to Hamas is therefore present if the donor knows the character of that organization.

The Court also said in Farmer v. Brennan that it was no defense that "he [a particular prison official] did not know that the complainant was especially likely to be assaulted by the specific prisoner who eventually committed the assault." 511 U.S. at 843, 114 S.Ct. 1970. That brings us to our next question — the standard of causation in a suit under sec