Federal Communications Commission (FCC)
445 12th Street SW
Washington, DC 20554
Phone: (888) CALL-FCC (888-225-5322)
Regulates U.S. telecommunications services, including radio, television, telephone, wire, satellite, Internet and cable. The Consumer Help Center has information on consumer rights and online complaint forms.
Federal Bureau Of Investigation (FBI)
Scams And Safety Web Page
This FBI Web page has information about many types of fraud and has links to report complaints, submit anonymous tips and more.
Headquartered in Washington, D.C., the FBI has field offices around the country; find a list with contact information here.