FBI investigators have broadened their probe into emailed bomb threats at the University of Pittsburgh to an anonymous remailer in Austria. Police visited Christian Mock, an Austrian provider who offers anonymous remailing services. Authorities had a court order allowing them to create a forensic disk image of the remailing service. Mock announced the remailser s private keys had been compromised during the police search and he d destroyed all existing keys, which would cause messages in transit using those keys to be discarded.
Source: https://threatpost.com/fbi-targets-austrian-remailer-pitt-bomb-threat-case-042612/76492/