Cartons of mail ready to be sorted sit on a shelf at the U.S. Post Office sort center. - 

This final note today, just because we haven't said the words Edward Snowden or government monitoring on the broadcast yet.

The New York Times has a story today in which readers learned this fact: The United States Postal Service takes pictures of every single piece of paper mail it processes in this country. That's photographs of 160 billion cards and letters last year.

It's used for law enforcement, mostly. All police, sheriffs and the FBI have to do is ask, and the post office will tell 'em what kind of mail you've been getting for the past four months.

Follow Kai Ryssdal at @kairyssdal