Last month, the Fourth Circuit held in In re GNC Corp. that "to state a false advertising claim on a theory that representations have been proven to be false, plaintiffs must allege that all reasonable experts in the field agree that the representations are false.” — F.3d –, 2015 WL 3798174, at *7 (4th Cir. June 19, 2015). Yes, you read that correctly: without unanimity among experts, a false advertising case must be tossed. This holding came in a case brought by consumers under various state consumer protection laws. But the court did not directly construe those laws. Rather, it analogized to its understanding of precedents under section 43(a) of the Lanham Act.
A group of academics led by Georgetown Law prof Rebecca Tushnet have filed this amicus brief arguing that the Fourth Circuit misunderstood "false advertising" under the Lanham Act and the legal concept of "falsity" more generally.
The plaintiffs' petition for rehearing and rehearing en banc challenges both the Fourth Circuit's understanding of falsity and its use of Lanham Act precedents rather than precedents under the Federal Trade Commission Act (on which many state consumer protection laws are based).
