The Justice Department has confirmed that Attorney General Jeff Sessions has expressed a “growing concern” that social media giants may be “hurting competition” and “intentionally stifling” free speech and expression.

The comments come as Facebook chief operating officer Sheryl Sandberg and Twitter chief executive Jack Dorsey gave testimony to the Senate Intelligence Committee on Wednesday, as lawmakers investigate foreign influence campaigns on their platforms.

Social media companies have been under the spotlight in recent years after threat actors, believed to be working closely with the Russian and Iranian governments, used disinformation-spreading tactics to try to influence the outcome of the election.

“The Attorney General has convened a meeting with a number of state attorneys general this month to discuss a growing concern that these companies may be hurting competition and intentionally stifling the free exchange of ideas on their platforms,” said Justice Department spokesman Devin O’Malley in an email.

It’s not clear exactly if the Justice Department is pushing for regulation or actively investigating the platforms for issues relating to competition — or antitrust. Social media companies aren’t covered under U.S. free speech laws — like the First Amendment — but have long said they support free speech and expression across their platforms, including for users in parts of the world where freedom of speech is more restrictive.

Spokespeople for Facebook and Twitter declined to comment