Facebook Acquisitions Benefitted Its Employees, Sellers, and Consumers. Where Is the Harm?

The claim by the Federal Trade Commission (FTC) and 48 state attorneys general that Facebook’s acquisition of Instagram and WhatsApp qualifies as anticompetitive behavior foolishly focuses on the motivations of the world’s largest social-media firm and ignores what those acquisitions have meant for consumers.

In the filings, the FTC and the states allege that Facebook snatched up the picture-sharing and messaging apps to prevent them from becoming a competitive threat. Perhaps it did. Maybe Facebook was indeed worried about being displaced as the market leader. But what does its motivation...