The Transportation Security Administration told employees to stop posting to TikTok on Sunday, according to CBS News.

The TSA’s announcement to ban employees from using TikTok came shortly after Sen. Chuck Schumer (D-NY) penned a letter to its administrator, David Pekoske, requesting that the agency halt its use. According to The Hill, TSA employees have used TikTok to create and post videos explaining some of the agency’s boarding processes and rules.

“TSA has never published any content to Tik Tok nor has it ever directed viewers to Tik Tok,” a TSA spokesperson told The Verge. “A small number of TSA employees have previously used Tik Tok on their personal devices to create videos for use in TSA’s social media outreach, but that practice has since been discontinued.”

“TSA has never published any content to Tik Tok”

The Department of Homeland Security, which houses the TSA, banned the use of TikTok from government-issued devices last month. Schumer cited this policy in his letter on Saturday. In December, the US Army banned soldiers from using the app, too.

In an attempt to assuage lawmaker concerns over the security of the app, TikTok’s parent company, ByteDance, announced that it was seeking to hire an American CEO based in Washington, DC. The company is also looking to hire a DC-based director of content moderation policy, as first reported by Tonya Riley from The Washington Post.