Hacktivist group Anonymous took control of the U.S. Sentencing Commission website Friday, January 25 in a new campaign called "Operation Last Resort."
The first attack on the website was early Friday morning. The second - successful - attack came around 9pm PST that evening.By 3am PST ussc.gov was down (it had been dropped from the DNS), yet as of this writing the IP address (188.8.131.52) still returned the defaced site's contents.
Update January 26, 8pm PST: ussc.gov is restored.
It appears that via the U.S. government website, Anonymous had distributed encrypted government files and left a statement on the website that de-encryption keys would be publicly released (thus releasing the as-yet unkonwn information held on the stolen files) if the U.S. government did not comply with Anonymous' ultimatum demands for legal reform.