More than eight years ago, an investor contacted Instagram co-founder Kevin Systrom to inform him that Mark Zuckerberg was interested in buying the fast-growing photo-sharing app. Mr. Systrom’s first question was direct: would the Facebook Inc. chief executive go into “destroy mode” if told no?
That question of how Facebook used its considerable market power to grow through strategic acquisitions was a big one in Wednesday’s antitrust hearings, with the Instagram deal as the starring episode thanks to new documents released…