This past weekend 4Chan members launched distributed denial-of-service attacks on the websites of both the MPAA and the RIAA, taking the sites down for long periods of time on Saturday.
TorrentFreak reports that on Saturday 4Chan's 'Anonymous' launched a DDoS attack on Aiplex Software, an anti-piracy outfit hired by the MPAA to launch DDoS attacks on torrent sites that failed to respond to copyright infringement notices sent by the MPAA. Once Aiplex went down, 4Chan moved on to bigger and better targets.
"How fast you are in such a short time! Aiplex, the bastard hired gun that DDoS’d TPB (The Pirate Bay), is already down! Rejoice, /b/rothers, even if it was at the hands of a single anon that it was done, even if ahead of schedule. now we have our lasers primed, but what do we target now?
We target the bastard group that has thus far led this charge against our websites, like The Pirate Bay. We target MPAA.ORG! The IP is designated at “216.20.162.10″, and our firing time remains THE SAME. All details are just as before, but we have reaimed our crosshairs on this much larger target. We have the manpower, we have the botnets, it’s time we do to them what they keep doing to us.
REPEAT: AIPLEX IS ALREADY DOWN THANKS TO A SINGLE ANON. WE ARE MIGRATING TARGETS."
According to TorrentFreak, the assault on MPAA.org was successful; the site was taken offline within minutes and remained down for 18 hours until the MPAA moved its site to another IP address.
4Chan continued their efforts on Sunday and with the help of sympathizers, took down the RIAA website with a separate attack. The RIAA attack was scheduled for 3 p.m. Eastern Time and the site went down five minutes before that time.
Both the MPAA and Aiplex confirmed to the BBC that DDoS attacks were responsible for site downtime over the weekend.
Sources: Torrent Freak, BBC

there is a single botnet herder capable taking out a website, just one.... thats frightening to think of, especially seeing as the site that they took down was for all intent a botnet herder themselves
saying that, i couldn't help but grin from cheek to cheek when i read the title
Anon may be able to take down a website, but the *#AA's own our politicians, and the politicians control the enforcers. this will do nothing more than escalate the situation. They changed IP's now what, another DDos, new ip then what? Am i the only one who thinks these guys are playing a game of mental masturbation, look what we did, I feel so much better now..
sheesh