SAN FRANCISCO — When Edelson PC, the Chicago-based plaintiffs firm, opened an office in San Francisco a little more than a year ago, it set the privacy defense bar abuzz.

Though small, the firm’s focus on privacy actions had made it a thorn in tech’s side, leading the New York Times to declare founder Jay Edelson “if not the most hated person in Silicon Valley, very close to it.”For lawyers who defend Valley companies against privacy suits, there was one obvious conclusion: the Edelson thorn was about to become just a bit more painful.