As the Senate considers the bill that would force a sale or ban of TikTok, lawmakers have heard directly from intelligence officials about the alleged national security threat posed by the app. Now, two prominent senators are asking the office of the Director of National Intelligence to declassify and make public what they have shared.

“We are deeply troubled by the information and concerns raised by the intelligence community in recent classified briefings to Congress,” Democratic Senators Richard Blumenthal and Republican Senator Marsha Blackburn write. “It is critically important that the American people, especially TikTok users, understand the national security issues at stake.”

The exact nature of the intelligence community's concerns about the app has long been a source of debate. Lawmakers in the House received a similar briefing just ahead of their vote on the bill. But while the briefing seemed to bolster support for the measure, some members said they left unconvinced, with one lawmaker saying that “not a single thing that we heard … was unique to TikTok.”

According to Axios, some senators described their briefing as “shocking,” though the group isn’t exactly known for their particularly nuanced understanding of the tech industry. (Blumenthal, for example, once pressed Facebook executives on whether they would “commit to ending finsta.”) In its report, Axios says that one lawmaker “said they were told TikTok is able to spy on the microphone on users' devices, track keystrokes and determine what the users are doing on other apps.” That may sound alarming, but it’s also a description of the kinds of app permissions social media services have been requesting for more than a decade.

TikTok has long denied that its relationship with parent company ByteDance would enable Chinese government officials to interfere with its service or spy on Americans. And so far, there is no public evidence that TikTok has ever been used in this way. If US intelligence officials do have evidence that is more than hypothetical, it would be a major bombshell in the long-running debate surrounding the app.