This is interesting. Wonder if UPS or FedEx do this.
Check it out:

The Postal Service takes pictures of every piece of mail processed in the United States — 160 billion last year — and keeps them on hand for up to a month.

In an interview with The Associated Press, Postmaster General Patrick Donahoe said the photos of the exterior of mail pieces are used primarily for the sorting process, but they are available for law enforcement, if requested.

The photos have been used “a couple of times” by to trace letters in criminal cases, Donahoe told the AP on Thursday, most recently involving ricin-laced letters sent to President Barack Obama and New York Mayor Michael Bloomberg.

“We don’t snoop on customers,” said Donahoe, adding that there’s no big database of the images because they are kept on nearly 200 machines at processing facilities across the country. Each machine retains only the images of the mail it processes.

Continue reading on www.washingtonpost.com