In a seemingly unprecedented move, a co-founder of one of the world's largest companies is actively working with the U.S. federal government to break it up.

Facebook co-founder Chris Hughes has participated in multiple recent meetings about breaking up the tech giant with the Federal Trade Commission, the Justice Department, and a number of state attorneys general, according to the New York Times. The news follows Facebook's admission on Wednesday that it was being investigated by the FTC on antitrust grounds, on the same day it was fined a record $5 billion by the federal agency for violating users' privacy.

Plenty of founders leave their companies. Some even build new companies that compete directly against their old ones. Hughes' actions go significantly further, starting in May with his explosive New York Times op-ed titled "It's Time to Break Up Facebook." Since then, Hughes has reportedly worked with antitrust law professors Scott Hemphill of New York University and Tim Wu of Columbia University to pitch U.S. regulators on the idea.

The trio's argument centers around Facebook's acquisition strategy, and how the purchasing of rival technologies can strengthen a company's hold on an industry monopoly. Examples of such deals are likely to include Facebook's purchases of WhatsApp for $19 billion in 2014 and Instagram for $1 billion in 2012.