The social media company now faces four concurrent investigations into its practices, including two by state agencies. It is currently being investigated for antitrust violations in the by the Federal Trade Commission, the House of Representatives Judiciary Committee and a bipartisan group of attorneys general.

It is not yet known what exactly the Justice Department's investigation will focus on. The FTC investigation is believed to be looking into Facebook's purchases of other companies like Instagram and WhatsApp, while the Judiciary Committee investigation is focusing on whether Facebook engaged in anticompetitive behavior along with Apple, Amazon and Google. The group of attorneys general are looking into whether Facebook has impeded customer choice.

The Justice Department may be looking into Facebook as part of its recently launched antitrust review of technology companies, including issues involving search and social media. There has been speculation that this investigation would also be looking at Facebook's acquisitions, leading to criticisms from some lawmakers that there could be overlap between the Justice Department's work and the FTC's probe.