It is a violation of federal law for anyone to open mail other than the addressee or the government. A U.S. code stipulates that anyone who takes an item of mail from a post office, mail depository or postal carrier before it is delivered to the addressee or opens, hides or destroys mail shall be fined, imprisoned for up to five years, or both.
Certain exceptions to the rule exist. For example, it is acceptable for executives to delegate the opening of their mail to secretaries. Those with powers of attorney can open mail for those they represent. Military mail addressed to deployed soldiers can be censored for security and morale issues. Postcards are already open and can be freely read by third parties.
The U.S. Postal Inspection Service is the law enforcement and security arm of the U.S. Postal Service. Its function is to enforce more than 200 federal laws and investigate crimes concerning the fraudulent use of the USPS. Among the statutes it enforces are those concerning the destruction, obstruction and delay of mail. Postal customers are legally entitled to receive their mail intact and free from outside interference. Similar areas of investigation concern mail theft or the stealing of mail before it reaches the intended recipient and mail fraud, which is the misuse of mail in perpetrating various types of scams.