(The Center Square) – A new effort in Congress may ban lawmakers from using TikTok for official communications.

A coalition of House and Senate Republicans sent a letter to Congressional leadership calling on them to change the House and Senate rules to bar lawmakers from using TikTok, calling it a “de-facto spyware app.”

“It is troublesome that some members continue to disregard these clear warnings and are even encouraging their constituents to use TikTok to interface with their elected representatives – especially since some of these users are minors,” the letter said.

State laws on TikTok vary, but many state governments have already taken action. According to the American Legislative Exchange Council, there are 150 million active TikTok users in the U.S., an increase from 100 million in 2020.

"It's definitely standard practice especially in the U.S. House and especially for those who serve on sensitive committees like Intelligence Committee, that certain applications are not allowed to be on devices," Jake Morabito, director of the Communications and Technology Task Force for ALEC, told The Center Square.

TikTok CEO Shou Zi Chew testified before Congress in March, but his testimony largely intensified concerns instead of alleviating them.

Chew tried to assuage fears at the hearing, saying the company has been working for two years on “what amounts to a firewall to seal off protected U.S. user data from unauthorized foreign access.”

Taking Chew to task was not limited to Republicans. Democrats expressed concerns as well.

“While this hearing shines a light on TikTok, this hearing should also serve as a call to action for the Congress to act now to protect Americans from surveillance, tracking, personal data gathering, and addictive algorithmic operations that serve up harmful content and has a corrosive effect on our kids’ mental and physical well-being,” Rep. Kathy Castor, D-Fla., said at the hearing.

The concerned legislators said even after the added proof given at that hearing, TikTok continued collecting data.

“Even after the March 23, 2023, hearing, in which it became blatantly clear to the public that the China-based app is mining data and potentially spying on American citizens, members of Congress continue to utilize the app to communicate with their constituents,” the letter said.

Federal employees are currently banned from using the app on government devices.

“We feel this situation warrants further action to protect the privacy of both sensitive congressional information and the personal information of our constituents,” the letter said. “To that end, we urge you to enact a change to the Senate and House rules to ban members of Congress from using TikTok for official use.”