As you say they have stopped SOPA, they have taken down megaupload.com. As this has been taken down by the government, a group called “Anonymous” have given no mercy. On the 19th of January, when megaupload was taken down. This group decided they wanted revenge and weren’t playing nice.
Evidence: http://www.youtube.com/watch?v=N2WqU-HvyUI&feature=player_embedded
Anon (Otherwise known as Anonymous) are a group hackers, who have retaliated with the downing of Megaupload, well, not so well. As a response to the governments act, they went on a ‘Revenge Spree’
they have taken down Government sites such as; justice.gov, USDOJ.GOV, copyright.gov, www.responsibleinvestment.org, mpaa.org.
After those they have decided to attack major music labels to such as; http://universalmusic.com/ and www.bmi.com/.
Alot of of infected sites are either completely shut down, or just really really slow.