The U.S. Postal Services now photographs the exterior or every package and letter it processes. Critics decry it an another encroachment of civil liberties while proponents say it can be a valuable tool to combat terrorism.

Read about the little know practice of mail logging in the New York Times: http://www.nytimes.com/2013/07/04/us/monitoring-of-snail-mail.html?pagewanted=all&_r=0