The U.S. Court of Appeals for the Fourth Circuit last week kept intact a key part in the Federal Trade Commis­sion’s “arsenal,” upholding a $163 million judgment against a woman who allegedly helped dupe consumers into buying computer-security software.

It was a high-stakes dispute, but not just because of the money — how much the FTC will actually collect is unclear. Rather, the defendant, Kristy Ross, mounted a novel and potentially devastating challenge to the FTC’s ability to use its go-to statute, the FTC Act, to collect money and hold individuals liable.