The devices are largely accurate, sources say, and can even determine what type of device is in the room. When the ban was first implemented several months ago, a group of lawmakers was waiting for the president in the West Wing while a sweep was being carried out. The device picked up a Samsung Galaxy, which was in the pocket of one of the visiting lawmakers, according to a source familiar with the situation.

So far, however, not even Trump’s Men in Black-style specialists have had much of an impact. In March, a somewhat unprecedented leak of the president’s official briefing materials prompted yet another news cycle about his cozy relationship with Vladimir Putin. (Trump was reportedly “infuriated” by the leak, and quizzed outside allies on which staffer they thought was responsible.) In the past few months alone, chatty White House sources have dished up damning information on the Rob Porter debacle, Hope Hicks’s departure, the Russia legal defense squad’s game of backstabbing musical chairs, the firings of several Cabinet-level officials, and the increasing sense of doom surrounding Kelly’s own tenure as chief of staff.

As recently as last week, a private comment by White House staffer Kelly Sadler—that John McCain’s vote didn’t count for much, considering he’s “dying anyway”—made its way into the news cycle, infuriating press secretary Sarah Huckabee Sanders, who reportedly scolded a room full of press aides for leaking the remark. “I am sure this conversation is going to leak, too. And that’s just disgusting,” she said, per a source speaking to Axios. (And, of course, she was right.)

West Wing spy hunters might have better luck if they could only silence the aggrieved serial leaker at the top. Instead, the White House strategy has been to close ranks and rail against the media for its reliance on the unfaithful. “I think it is disgusting and some of the most shameful behavior that you could ever engage in,” Sanders said on Fox & Friends Wednesday, referring not to the comment about McCain, but the fact that it got out. “It’s an honor to work for the president and to be part of his administration. Anybody who betrays that . . . is a total and complete coward and they should be fired.” The real problem, as Matt Schlapp—the husband of White House Communications Director Mercedes Schlapp—told CNN on Monday, is “people who have an animus against [Sadler], and that’s the problem in this White House.” President Trump himself was more gnomic in his comments on Twitter. The “so-called leaks coming out of the White House are a massive over exaggeration put out by the Fake News Media in order to make us look as bad as possible,” he explained. “With that being said, leakers are traitors and cowards, and we will find out who they are!”