President Donald Trump will be none too pleased that the “single greatest witch hunt of a politician in American history” just got greater. In the wake of last week’s revelation that Facebook sold $100,000 worth of fake news ads to phony Russian bot accounts during the election, we’ve also learned that Facebook claims they have no idea how far that ad buy may have spread nor had they any idea that their platform allowed buyers to purchase ads targeting groups with interests like "Jew hater” and “How to burn jews.” Special prosecutor into the Russian meddling Robert Mueller, however, seems to have a knack for getting information from Facebook that they’d previously claimed to not know about or were unwilling to produce.

Bloomberg reports that Facebook has handed over troves of additional information to the special prosecutor that they did not disclose in their testimony last week to the Senate and House Intelligence committees. That’s based on Friday’s original report from the Wall Street Journal (which is behind a paywall) asserting that “Facebook Inc. has handed over to special counsel Robert Mueller detailed records about the Russian ad purchases on its platform that go beyond what the company shared with Congress last week.”

That account makes it sound like Facebook voluntarily gave up more information in the interest of being good citizens, which may be fake news (or more likely, aggressive message management by Facebook PR). Additional reporting by CNN tells us that Mueller served Facebook with search warrants to pry out copies of the some 3,000 Russian-bought ads that were not voluntarily made available in last week’s testimony to the congressional committees. Facebook’s privacy policy asserts that account records can only be disclosed if Facebook is handed a subpoena, a court order, or a search warrant. And apparently the privacy policy still applies, even when Facebook knows that you’re a Russian bot account.

While the squeeze here is being applied to Facebook, legal analysts assume that this means Mueller is connecting dots to charge foreign nationals or U.S. citizens with a crime. “Bob Mueller went to a federal judge and presented evidence and convinced the judge that a crime was committed involving foreign individuals contributing to a political election here in the United States through their actions on Facebook,” former federal prosecutor Renato Mariotti told CBS News this weekend. “[Mueller] would have to sort of lay out evidence showing that this crime had occurred, not just merely say so, but actually, you know, records that he had obtained, testimony that had been given or interviews that people gave to the FBI, that prove to this judge that there is a good reason to believe that a crime had occurred. It's a very serious and significant move forward for the Mueller investigation.”

CBS 5 spoke to a former FBI agent who worked under Mueller for some additional tea-leaf reading context on what the issuing of this search warrant means. “Companies have to recognize the search warrant, they can be held in contempt,” former assistant special agent of the San Francisco FBI Jeff Harp told CBS 5. “And who gets held in contempt? Well, the CEO can be held in contempt.”

The fact that Facebook has been substantially more forthcoming to Mueller’s team than they have been toward congressional investigators has not gone unnoticed by, naturally, congressional investigators. “It was my belief that the Russians were using those sites to interfere in our elections, and the first reaction from Facebook was, ‘No. You’re crazy,’” Senate Intelligence Committee chairman Mark Warner complained to Reuters last week, following Facebook’s testimony. “I think what we saw yesterday in terms of their brief was the tip of the iceberg.”

As CNet points out, we’ve seen a real sea change in Facebook and Google’s attitudes toward whether they unwittingly allowed foreign influences on their platform to affect the 2016 U.S. election. Facebook, currently responding to search warrants, originally called such claims a “crazy idea.” Google, for their part, claimed there was “no evidence” bots bought any ads for the 2016 election on their platform, yet for some reason banned fake news sites from Google AdSense the week after the election.

Related: Newly Appointed Special Counsel Robert Mueller Spent Much Of His Career In San Francisco