If Twitter is Donald Trump’s ultimate weapon, it has also been his greatest liability. Back in November, the president nearly compromised two separate foreign-policy initiatives by re-tweeting a series of extremist videos. Earlier that month, he’d called for a New York terrorist to receive the death penalty, instantly complicating his trial. And, of course, he effectively blew up his own administration’s legal argument for its Muslim travel ban, all via tweet. So far, Trump’s penchant for self-sabotage has primarily made life a living hell for other people. According to The New York Times, however, the president’s online spewage may finally have arrived at his own doorstep.

Per the Times, Robert Mueller’s office has notified Trump’s legal team that it plans to examine his Twitter history for evidence of obstruction of justice—specifically, tweets he sent attacking people like former F.B.I. director James Comey and Attorney General Jeff Sessions. (Trump eventually fired Comey, while under his rule, Sessions has slowly and systematically been stripped of human dignity.) The inquiry, three sources told the Times, centers around statements tweeted by Trump while he was “privately pressuring” both Comey and Sessions to drop the investigation, raising the question as to whether his online tirades could be considered a form of public intimidation.

The bar for obstruction cases is necessarily quite high. As my colleague Abigail Tracy has reported, prosecutors must be able to establish that the defendant acted with corrupt intent—hardly a simple thing to prove, especially without evidence of an underlying crime. On their own, Trump’s tweets are unlikely to constitute obstruction of justice. But added to the infinite pile of other Trump wrongdoings over the past two years—floating pardons to potential witnesses, making misleading statements, and, of course, attempting to sway the public against the investigation—Mueller could, several legal analysts told the Times, make the case for a larger pattern of behavior. “There’s rarely evidence that someone sits down and says, ‘I intend to commit a crime,’ so any type of investigation hangs on using additional evidence to build a narrative arc that hangs together,” said Samuel W. Buell, a professor of law at Duke University and former senior federal prosecutor. “That’s why a prosecutor wants more pieces of evidence. You need to lock down the argument.”

The new inquiry likely gives Trump’s legal team nightmares, considering that they’ve reportedly begged him to stop tweeting about the investigation since early 2017. But at this late date, hoping to rein in the president might be pointless. To wit, Rudy Giuliani, one of Trump’s newest lawyers, has already offered up his counter-argument in the case that Mueller puts the president’s Twitter account on the stand. “If you’re going to obstruct justice, you do it quietly and secretly,” he told the Times—“not in public.”