The sanctity of the mail, its security and privacy, forms the basic trust between the sender and the postal service. Not only do Americans expect their mail pieces to travel safely through the mail, but also that the system is kept secure from illegal use. Mail is to remain unopened and private between the time it leaves the sender’s hands and is delivered to the recipient. Congress has bent the tampering rules during wartime, but on the whole, once an item enters the mail stream, it is protected by the postal service against all threat.
Crimes involving a mail piece are generally directed at the valuables contained in the item, from simple theft of packages to infamous train robberies. Those who process and carry the mail or buildings that house it also suffer threats. Mail crimes sometimes include those that use mail as a vehicle for the crime itself, such as consumer fraud, drug smuggling, insider trading, or mail bombs.
