US antitrust enforcement is coming back from the dead

As tech companies acquired billions of users, and competition has withered, the United States paid only passing interest to antitrust concerns. Facebook’s acquisitions of WhatsApp and Instagram were approved without a hitch; Amazon successfully crushed other online retailers by temporarily lowering prices; Google began promoting its own search results (and affiliate marketing links) over those of competitors like Yelp and Expedia.
But perceptions of the internet giants began to turn in th