The Justice Department appears to be continuing a policy of disregarding search warrants when seeking to monitor activity on the Internet. The American Civil Liberties Union says internal documents show federal prosecutors and the FBI believe they are not compelled to obtain court-approved warrants to review emails and instant messages. The U.S. attorney’s office in New York circulated a memo saying a subpoena signed by a prosecutor, not a judge, is sufficient. By contrast, the IRS has publicly vowed to abandon warrantless spying of Internet use.