Despite attempts to play down the use of Facebook amongst Capitol Hill rioters, the social media giant is furnishing the feds with data on users who took part in the siege, including their private messages, after calls from lawmakers to do so.

In a criminal complaint filed against New York resident Christopher M. Kelly on Wednesday, a search warrant on his Facebook account was revealed. After being tipped off about Facebook posts from an account belonging to Kelly containing images of him at the storming of the U.S. Capitol on January 6, the FBI sought his private messages, as well as his linked IP address, phone number and Gmail address.

Amongst the data provided by Facebook were private messages with other users. When one contact told him to stay safe and to be on the lookout for Antifa, a far-left organization, he responded: “I'll be with ex-NYPD and some Proud Boys. This will be the most historic event of my life.” The Proud Boys is a far-right organization, members of which took part in the siege of the Capitol. From the messages, the FBI believes Kelly’s brother is a retired police officer and he’d planned to go to the Capitol with his sibling.

According to the complaint, in another chat, on January 9, Kelly posted a photograph that appeared to show him with his top off, brandishing an American flag in front of the Capitol, telling the recipient: “That’s me,” and, ”My brother took it.”

In a private message sent to a group chat on January 6, he wrote: “Tear gas, police, stopped the hearing, they are all headed to the basement.” And later: “F**k these snakes. Out of OUR HOUSE!”

The IP log history provided by the social media giant was useful, too, showing IP address locations indicating he had traveled from New York to Silver Spring, Maryland, near Washington, D.C., on January 6.

There’s no indication that Kelly has been arrested, though an arrest warrant has been issued. No lawyer has been listed, and Forbes couldn’t find any contacts for Kelly. He remains innocent until proven guilty.

Facebook chief operating officer Sheryl Sandberg had stated shortly after the mob attack on the Hill that the protests were largely organized on smaller, fringe social media sites. She was subsequently criticized as evidence mounted that numerous Facebook groups and accounts, public and private, were used to help organize the protest. Some contained violent threats. And whilst Parler was used by many of those who attended, the DOJ has filed numerous charges against individuals who were both planning their visit to Washington, D.C., and posting about their attendance on Facebook.

As per an analysis by the Program on Extremism at the George Washington University earlier this week, social media was referenced in 78% of 92 criminal complaints filed in the Justice Department’s investigations into the riots. Of those, 38% included social media posts from an individual who was subsequently charged.