Free speech activists at the Free Press and the Free Press Action Fund are calling upon the Federal Communications Commission to address “its crackdowns against First Amendment freedoms during recent meetings.”

“We write to express grave concerns about recent actions that call into serious question the Federal Communications Commission’s commitment to fostering free expression,” reads a letter authored by Free Press and Free Press Action Fund Deputy Director and Senior Counsel Jessica J. González and Policy Director Matt Wood. “In particular, the actions of FCC security and other FCC staff have chilled free speech and public participation in FCC decision-making processes that are supposed to be open to the public.”

The letter details a series of incidents in which the federal agency and members of its security staff have silenced dissenting voices, manhandled a reporter and barred members of the public from attending the agency’s monthly open meeting without due process.

During one incident, on the morning of March 23, 2017, two Free Press Action Fund members, Joe DeGeorge and David Combs, attempted to attend the FCC’s open meeting wearing plain white T-shirts that read “Protect Net Neutrality” in black letters. FCC security personnel informed the two that they would not be allowed to enter the public meeting room unless they removed the T-shirts or flipped them inside out to conceal their message.

“This was a clear-cut violation of Mr. DeGeorge’s and Mr. Combs’ constitutional right to free speech,” the letter says. “The Supreme Court has repeatedly held that the First Amendment safeguards people’s rights to express their disagreement with government policies, even in limited public forums like the FCC meeting room.”

The incident wasn’t an isolated event, the groups allege, “but one in a growing series of FCC efforts to stifle free speech and public participation at open meetings.”

“Many of these attempts to limit public speech and participation have targeted those who question or disagree with FCC Chairman Ajit Pai and the Trump administration over their plans to limit free speech on the internet by repealing net neutrality rules,” they claim.

The groups are calling on the agency to apologize to those targeted, and respond to a list of demands, including p”roviding a clear explanation of the FCC policy to protect the First Amendment rights of the public and reporters to peacefully participate in future agency open meetings.”