Here are 2 items for your consideration regarding U.S. Mail.
1) Further down this blog site at 7/15/13 (Tracking Your Mail) you will find reporting on the government program to scan and retain indefnitely all information on the outside of letters and parcels. You put your return address on something and it goes into the government data banks where it will remain forever or until your name (or one similar to yours) comes up and they take a look at who you have been corresponding with.
You have a health plan via Wellstar or subscribe to Comcast, then they know it and it is just a very short step for them to get hold of your medical records and find out what you like to watch on TV!
Suggestion: DO NOT put any return address on outgoing mail! Do not put any info on any envelope or package that you don't want to have in those massive government computers in Utah.
2) Just for your own satisfaction, those postage stamps having US Flags on them - affix them upside down. It is a very minor act of protest but what else is left for us to do to show we are concerned about where we are going as a country.