Twitter user @Anonymous Own3r gained several thousand new followers this afternoon after he (assuming it's a he) claimed responsability for the DNS attack on GoDaddy.

 

Anonymous Own3r's Twitter profile states he is "Security leader of #Anonymous (~Official member~)"

Anonymous Own3r had just over 2000 followers after the attack was launched.  By 6PM EDT that number had grown to over 5000 followers.

Anonymous members, a loose confederation of computer hackers, are characterized either Guy Fawkes masks or the logo seen on the flag below.

An excellent look inside Anonymous appeared this summer in Wired Magazine.