Federal Government Access to Telephone Records

Does the federal government have unrestricted, on-demand access to our telephone records? If it does, is that access lawful without a court order?

On May 17, 2006, the US Library of Congress, Congressional Research Service provided Congressional requestors with its report entitled Government Access to Phone Calling Activity and Related Records: Legal Authorities. The 19-page report summarizes "...statutory authorities regarding access by the Government, for either foreign intelligence or law enforcement purposes, to information related to telephone calling patterns or practices." The report also discusses statutory prohibitions against accessing or disclosing such information, along with relevant exceptions to those prohibitions.