Federal Law Enforcement Tracks Credit Card Use without Warrants
Federal law enforcement agencies don’t have to seek a court order to conduct real-time surveillance of credit card transactions of individuals. All that’s required is the filing of an administrative subpoena, which does not involve getting a judge to sign-off on the tracking and then presenting the subpoena to a credit card company’s security department. Courts do, however, order banks to not disclose to customers that law enforcement is watching their credit card activity.
Real-time tracking is also conducted on car rental agencies, airline reservations and shopping clubs.
http://www.allgov.com/Controversies/ViewNews/Federal_Law_Enforcement_Tracks_Credit_Card_Use_without_Warrants_101204