Article here: Copy of Postal Service Audit Shows Extent of Mail Surveillance. Re-posted from /r/privacy.
tl;dr postal metadata is often collected illegally; not handled professionally or with proper oversight; likely used to develop a case against a suspect without probable cause
Wow. Only a thousand requests for 200 million people. Probably most of them are suspected terrorists, spies or tax dodgers.
Americans finally have the proof you need to stop worrying. Only one in 200,000 of you are having your mail "watched".
It won't make any difference. Even though the short-staffed agencies can't keep tabs on the spies and terrorist cells, you will convince yourself that they've made an exception just for you, and dropped everything to monitor a student who bought some cannabis edibles once.