In a self-described act of revenge, Anonymous has lashed out against regulatory groups blamed for today's raid on Megaupload, bringing down the websites of Universal Music Group, the Department of Justice, the RIAA and the MPAA.

At the time of this writing, attempts to bring up each of the aforementioned websites were unsuccessful. A Twitter account claiming to speak for the rogue hacker collective has subsequently deemed the crashes a sweet victory.

"HUGE RETALIATION AGAINST THE DOWN OF MEGAUPLOAD IS UNDERWAY!" @anondaily wrote, before claiming "tango down" after the collapse of the Deparment of Justice's website.

The hackers are most likely using Distributed Denial of Service attacks, a preferred tactic of Anonymous that involves sending a flood of information to targeted web servers in an effort to bring them down.

Megaupload was shuttered and its founders were charged with criminal piracy earlier this afternoon.

[via Gizmodo]