After a noteworthy lack of action on during the SOPA blackouts on January 18th, it seems that Anonymous is springing back into action in response to the federal takedown of MegaUpload and the subsequent arrest and likely extradition of Kim Dotcom. Just hours after the news that the U.S. federal government took down MegaUpload alongside an indictment on piracy charges, Universal.com and Justice.gov have gone down, and a prominent Anonymous affiliated Twitter account is claiming responsibility.
Knowing Anonymous, there is probably more to come both in the way of DDOS attacks and threats toward the federal government, SOPA supporters, and other organizations that have spearheaded copyright infringement lawsuits. More as the story develops.
Update: RIAA.org is now down.