From the Supreme Court's decision in Bridge v. Phoenix Bond & Indem. Co., 2008 U.S. LEXIS 4703 (U.S. June 9, 2008):

1. First Party Reliance Not Required. “[A] plaintiff asserting a RICO claim predicated on mail fraud need not show, either as an element of its claim or as a prerequisite to establishing proximate causation, that it relied on the defendant's alleged misrepresentations.”

2. First Party Reliance Not Dictated by § 1962(c). “[N]o showing of reliance is required to establish that a person has violated § 1962(c) by conducting the affairs of an enterprise through a pattern of racketeering activity consisting of acts of mail fraud.”

3. First Party Reliance Not Dictated by § 1964(c). Nor is any such showing required under § 1964(c): “[A] person can be injured ‘by reason of’ a pattern of mail fraud even if he has not relied on any misrepresentations.”

4. Elements of Common Law Fraud Irrelevant. It is irrelevant that reliance must be shown to establish common law fraud because: “Congress chose to make mail fraud, not common-law fraud, the predicate act for a RICO violation. And ‘the mere fact that the predicate acts underlying a particular RICO violation happen to be fraud offenses does not mean that reliance, an element of common-law fraud, is also incorporated as an element of a civil RICO claim.’ Anza, supra, at 476 (THOMAS, J., concurring in part and dissenting in part).”

5. Someone Presumably Must Have Relied. “Of course, none of this is to say that a RICO plaintiff who alleges injury "by reason of" a pattern of mail fraud can prevail without showing that someone relied on the defendant's misrepresentations. Cf. Field v. Mans, 516 U.S. 59, 66 (1995) (‘No one, of course, doubts that some degree of reliance is required to satisfy the element of causation inherent in the phrase “obtained by”’ in 11 U.S.C. § 523(a)(2)(A), which prohibits the discharge of debts for money or property ‘obtained by’ fraud).”

6. Presence or Absence of Reliance Is Relevant to the Issue of Causation (If Not Essential to It). “Proof that the plaintiff relied on the defendant's misrepresentations may in some cases be sufficient to establish proximate cause, but there is no sound reason to conclude that such proof is always necessary. By the same token, the absence of first-party reliance may in some cases tend to show that an injury was not sufficiently direct to satisfy § 1964(c)'s proximate-cause requirement, but it is not in and of itself dispositive. A contrary holding would ignore Holmes' instruction that proximate cause is generally not amenable to bright-line rules.”

One example used by the Supreme Court that has been decided differently by different courts: “[S]uppose an enterprise that wants to get rid of rival businesses mails misrepresentations about them to their customers and suppliers, but not to the rivals themselves. If the rival businesses lose money as a result of the misrepresentations, it would certainly seem that they were injured in their business "by reason of" a pattern of mail fraud, even though they never received, and therefore never relied on, the fraudulent mailings.” The issues now are causation in fact and proof.