FTC to investigate Facebook purchase of Instagram

U.S. antitrust regulators are hitting Facebook with more post-IPO angst.

The Federal Trade Commission is looking to give Facebook's proposed Instagram purchase "a lengthy investigation," Reuters reported today.

The commission sent a second request, dated May 16, to Facebook instructing the social-networking company to provide large amounts of data that the "regulators will sift through to ensure that the deal complies with antitrust law," according to an unnamed source.

This only heightens Facebook's woes, as the company's stock continues to slide, taking tens of millions off its $1 billion deal to buy Instagram.