DALLAS (CBS 11 NEWS) - A Dallas man is believed to be in federal custody after allegedly threatening an FBI agent on the internet.

That person, Barrett Brown is also a sometime spokesman for the “hacktivist” group called “Anonymous.”

In a recent YouTube posting railing against the FBI and the Zetas drug cartel, Brown said of federal agents, “And I will shoot all of them and kill them if they come and do anything because they are engaged in a criminal conspiracy.”

According to D-Magazine publisher Tim Rogers, Brown’s online rant was triggered when he felt the FBI was targeting his mother when agents recently searched both Brown’s home and his mother’s.

“And so he posted a video online where he threatened one agent in particular, threatened to look into his children,” Rogers said.

On the YouTube posting Brown is heard to say, “When I say his [the agent’s] life is over, I don’t say I’m going to kill him; but I’m going to ruin his life and look into his [expletive deleted] kids.”

Brown is a published author who’s written for national magazines, as well as Dallas’ D-Magazine.

Rogers did an award-winning profile on the author when Brown emerged as an occasional spokesman for the loosely organized computer hacking group known as Anonymous.

Much like Wikileaks, Anonymous hacks and posts government and corporate secrets…but it has also identified members of dangerous Mexican drug cartels; so Anonymous members fear reprisals.

The “hactivist” group has become such a force, that only this year, Time Magazine named Anonymous as one of the most influential groups of people in the world.

Brown was actually online in his Uptown apartment chatting with other individuals when the FBI came to arrest him. An unidentified woman was on his webcam when agents came in and......REST OF IT

VIDEO