Stefani Shanberg often counsels Silicon Valley companies about the perils of being hauled into court for patent infringement. But in the last couple of years she’s been warning her clients about another dangerous arena: the International Trade Commission.

“One of our clients got sued at the ITC and didn’t even know what it was,” said Shanberg, a partner at Perkins Coie’s San Francisco office. “Another client sent an e-mail attaching the complaint and asked me to find out what it was all about. Neither client understood what they had just gotten involved in.”