Self-styled Anonymous spokesman Barrett Brown has been arrested at his apartment and taken into FBI custody.
He was in the middle of an online video chat - see below - on Wednesday evening when Dallas law enforcement authorities stormed in. In the video, law enforcement officers can be heard shouting at Barratt, telling him to cooperate and put his hands down.
After a few minutes, the video is shut off by a woman in the room, but the audio continues to operate.
Brown's now been transferred to an FBI facility, Anonymous said in a tweet.
"I callad Dallas Co. Sheriff back. They confirmed @BarrettBrownlol has been released to the FBI. They didn't know name of agent who took him… or they wouldn't give it. Also, couldn't confirm if he had talked to a lawyer or had his meds w/ him." read the messages.
According to Anonymous, Brown's been arrested over his comments on a recent YouTube video about FBI agent Robert Smith, and faces trial for threatening a federal agent.
In the video - titled Why I'm Going to Destroy FBI Agent Robert Smith Part Three: Revenge of the Lithe - Brown accuses Smith of harassing his mother, and says he plans to ruin his life.
Brown's already been raided by the FBI once this year, as part of an investigation into the LulzSec hacks on Sony, the FBI and others.