The following excerpt is from the U.S. Department of Justice website:
Prosecution of Internet Hacktivist Group "Anonymous"
by Melinda Haag
U.S. Attorney for the Northern District of California
The United States Attorney's Office (USAO) for the Northern District of California and the Federal Bureau of Investigation (FBI) have been active in investigating and prosecuting the cyber attacks initiated by members of the Internet activist group "Anonymous" and/or its associates.
In late November 2010, WikiLeaks released a large amount of classified United States State Department cables on its website. Citing violations of its terms of service, and in response to WikiLeaks' release of the classified cables, PayPal suspended WikiLeaks' accounts so that WikiLeaks could no longer receive donations via PayPal. In retribution for PayPal's termination of WikiLeaks' donation account, Anonymous coordinated and executed distributed denial of service (DDoS) attacks against PayPal's computer servers. DDoS attacks are attempts to render a computer unavailable to users through a variety of means, including by saturating the target computers or networks with external communication requests, thereby denying service to legitimate users. The attack lasted from December 6, 2010 through December 10, 2010, and used an open-source computer program that the group made available as a free download on the Internet.
On January 27, 2011, the FBI executed twenty-seven search warrants in twelve states and the District of Columbia as part of the investigation of the DDoS attacks against PayPal. On July 13, 2010, a federal grand jury in San Jose, California, returned a fifteen-count indictment against Dennis Collins, Christopher Wayne Cooper, Joshua John Covelli, Keith Wilson Downey, Mercedes Renee Haefer, Donald Husband, Vincent Charles Kershaw, Ethan Miles, James C. Murphy, Drew Alan Phillips, Jeffrey Puglisi, Daniel Sullivan, Tracy Ann Valenzuela and Christopher Vo for conspiracy and causing intentional damage to PayPal's computer servers. The case, United States v. Dennis Collins, et.al., No. CR 11-00471 DLJ, is currently pending before the Honorable D. Lowell Jensen .
On July 19, 2011, the FBI arrested fourteen defendants. On that same day, the FBI executed an additional twenty-one search warrants in eleven states, also in connection with the DDoS attacks against PayPal. Investigation into the subjects of those searches is continuing.
On December 16, 2010, members of the "People's Liberation Front" (PLF), a hacking group associated with Anonymous, coordinated and executed a DDoS attack against Santa Cruz County's computer servers. The PLF launched the DDoS attack in retaliation for the City of Santa Cruz enacting and enforcing an anti-camping statute against the homeless and disbanding protests related to the anti-camping statute.
On September 21, 2011, a federal grand jury in San Jose, California, returned a three-count indictment against Christopher Doyon and Joshua John Covelli for conspiracy and causing intentional damage to the Santa Cruz County computer servers. The case, United States v. Christopher Doyon, et. al., No. CR 11-00683 DLJ, is also currently pending before the Honorable D. Lowell Jensen. On September 22, 2011, the FBI arrested Christopher Doyon.