Lina Khan became chair of the Federal Trade Commission two years ago on a promise to bring bold action against the biggest tech companies.
For too long, Ms. Khan said at the time, the agency had been a weak cop and needed to challenge behemoths like Microsoft, Amazon, Meta and Google in the courts to stem their growing power. Even if the F.T.C. lost the cases, she later added, they would be a partial victory because the agency would signal…