Sadly, you are mistaken. Domestic First Class mail can not be opened without a warrant, but any mail that crosses a border can be opened and searched at will. S

Sadly, you are mistaken. Domestic First Class mail can not be opened without a warrant, but any mail that crosses a border can be opened and searched at will. Source: https://www.schneier.com/blog/archives/2006/01/us_customs_open.html https://www.schneier.com/blog/archives/2006/01/us_customs_op...