This week’s antitrust suits against Facebook by the FTC and dozens of state attorneys general came a month after the Justice Department went to court to block Visa from buying a financial data startup called Plaid — on the grounds that, much like Facebook, the credit card giant is trying to neutralize a rising competitor by buying it. The FTC has also challenged two other recent proposed deals, one involving pharmaceuticals and the other DNA-sequencing technology, that it alleged were intended to cut off competition that didn’t yet exist.

That “legal revolution,” as one antitrust expert called it, has yet to be tested in court. But people following the issue say the Facebook suits could pave the way for more of these kinds of challenges.

“The legal and political environment around antitrust in Big Tech is super different now” from 2012, said John Newman, who spent three years as an antitrust prosecutor at the Justice Department. Back then, “people were out there making the claim that when a market is free there can’t be harm to consumers and antitrust doesn’t apply.”