The U.S. Postal Inspection Service is the law enforcement branch of the U.S. Postal Service, empowered by federal laws and regulations to investigate and enforce over 200 federal statutes related to crimes against the U.S. Mail, the Postal Service, and its employees. Postal inspectors investigate any crime in which the U.S. Mail is used to further a scheme, whether it originated in the mail, by telephone or on the Internet. The illegal use of the U.S. Mail determines a mail fraud. If evidence of a postal-related violation exists, postal inspectors may seek prosecutive or administrative action against a violator. Postal inspectors base their investigations of mail fraud on the number, pattern and substance of complaints received from the public.