Curiously, both Justice Kagan for the majority, and Justice Kennedy in dissent, rely on Judge Posner cases in Camretta v. Greene.

From Kagan:

Whatever interest S. G. might have were her municipal liability claim still pending (an issuewe need not and do not decide), we do not think S. G.’s dismissed claim against a different defendant involving a separate legal theory can save this case from mootness. See Commodity Futures Trading Comm’n v. Board of Trade of Chicago, 701 F. 2d 653, 656 (CA7 1983) (Posner, J.) (“[O]ne can never be certain that findings made in a decision concluding one lawsuit will not some day . . . control the outcome of another suit. But if that were enough to avoid mootness, no case would ever be moot”).

From Kennedy:

The Court’s analysis appears to rest on the premise that the reasoning of the decision below in itself causes Cam-reta injury. Until today, however, precedential reasoning of general applicability divorced from a particular adversejudgment was not thought to yield “standing to appeal.” Parr v. United States, 351 U. S. 513, 516, 517 (1956) (opin-ion for the Court by Harlan, J.). That is why “[o]nly one injured by the judgment sought to be reviewed can ap-peal.” Id., at 516; see also supra, at 1–6; e.g., Chathas v. Local 134 IBEW, 233 F. 3d 508, 512 (CA7 2000) (Posner,J.) (“Adverse dicta are not appealable rulings. They can cause harm, but not the sort of harm that the courts . . .deem to create a genuine controversy within the meaning of Article III of the Constitution. Judgments are appealable; opinions are not” (citations omitted));