The amendments to § 292 of the Patent Act by the America Invents Act in 2011 eliminating the qui tam action for false marking suits survived a constitutional challenge in Brooks v. Dunlop Mfg. Inc., No. C 10-04341 CRB, 2011 WL 6140912, (N.D. Cal. Dec. 9, 2011).  

In Brooks, the false marking plaintiff unsuccessfully argued that the retroactive application of the new law eliminating its qui tam standing violated due process and amounted to an unconstitutional “taking” by the federal government. 

The district court held that because Congress had “a legitimate legislative purpose by comprehensively reducing the costs and inefficiencies associated with the ‘cottage industry’ of false marking litigation that developed after the Federal Circuit’s decision in Forest Group, Inc.” the amendments do not violate due process. Id. at *5.

As to the “takings” contention, the court held that a “takings” claim requires a vested property interest.  Since the plaintiff had not obtained a final judgment in its false marking suit, the loss of the right to proceed with the false marking lawsuit to collect a share of the penalty, if the plaintiff prevailed on the merits, was not a vested property interest.  Hence, the takings claim failed because the plaintiff did not establish that “he ever acquired a constitutionally protected property interest” in the false marking suit.  Id. at *6.  

For additional discussion on this topic see Robert A. Matthews, Jr., Annotated Patent Digest § 34:103 Parties That Can Assert a False Marking Violation.