A recent federal appellate decision has unleashed a wave of whistleblower suits accusing companies of falsely labeling their products as covered by patents.

In December, a U.S. Court of Appeals for the Federal Circuit ruling steeply increased the potential fines in so-called “false marking” cases, from a typical $500 for an offense to hundreds of thousands, or even millions of dollars, depending on the number of items sold. Since the ruling, plaintiffs lawyers have filed more than 130 new lawsuits (pdf), and defense lawyers are bracing for more.