This past year has been chock full of uncomfortable revelations about Ring, the surveillance social network and home security hardware company acquired by Amazon for a reported $800 million, including reports of potentially disastrous internal security practices, an apparent disregard for user privacy, and wave after wave of detail on secret partnerships with local police. Today, in a letter addressed to Amazon CEO Jeff Bezos, five Democratic senators are asking for an explanation, citing potential threats to U.S. national security.

Much of the letter focuses on allegations that Ring’s Ukrainian office, where it conducts much of its research and development operation, allowed employees across the company to access customer video data whether they had any real need to or not. In January, The Intercept reported that this loose security atmosphere at Ring meant “if [someone] knew a reporter or competitor’s email address, [they] could view all their cameras,” per one source, who also recalled Ring engineers casually spying on and “teasing each other about who they brought home” after dates. “If hackers or foreign agents were to gain access to this data,” the letter states, “it would not only threaten the privacy and safety of the impacted Americans; it could also threaten U.S. national security.”

The letter is signed by Sens. Ron Wyden of Oregon, Chris Van Hollen of Maryland, Ed Markey of Massachusetts, Chris Coons of Delaware, and Gary Peters of Michigan.

Ring’s public relations team has generally responded to worrying reports about its corporate plans to “declare war” on the “dirtbag criminals that steal our packages” with a combination of denials and assurances that the company’s crime-fighting mission is one unequivocally in the public’s interest. But getting concrete answers from the horse’s mouth on how exactly the company handles data — and who else may be handling it — has proven difficult, despite the growing privacy and civil liberties implications of Ring’s bread-and-butter surveillance business.

Markey made some progress when Amazon earlier this month responded to a letter he sent previously, asking about the company’s controversial partnerships with local police departments. Amazon revealed that video funneled to police under the arrangements comes with few restrictions on use or retention.