Citizens who are aware of federal crimes should report them to local offices of federal law enforcement.

The primary federal law enforcement agencies that investigate domestic crime on the Internet include: the Federal Bureau of Investigation (FBI), the United States Secret Service, the United States Customs and Border Protection, the United States Postal Inspection Service, and the Bureau of Alcohol, Tobacco and Firearms (ATF) . Each of these agencies has offices conveniently located in every state to which crimes may be reported. Contact information regarding these local offices may be found in local telephone directories. In general, federal crime may be reported to the local office of an appropriate law enforcement agency by a telephone call and by requesting the "Duty Complaint Agent."

Each law enforcement agency also has a headquarters (HQ) in Washington, D.C., which has agents who specialize in particular areas. For example, the FBI and the U.S. Secret Service both have headquarters-based specialists in computer intrusion (i.e., computer hacker) cases.