Law Enforcement Records Names, Addresses on Outside of Envelopes Traveling through the mail

Here is an Orwellian story sure to make you go ...Hmmmm. Law enforcement request to record names, addresses and other information from the outside of letters and packages of suspected criminals every year since 1998, according to U.S. Postal Inspection Service data. Here is an article from USA Today: Law enforcement requests for postal info granted. Is sanctity of the mail limited only to internal contents?