Gee mutts,who is President?
Yeppers! or,
But backing up a bit, users of US Mail give possession of their
whatever to the USPS. The contents may be protected by regulation, but the address information is in the open, for the USPS to use. It's kind of analogous to a police officer stopping a car for a burnt out tail light and spotting an open bottle of beer or spirits in the cup-holder next to the driver.
As for a prisoner's mail being scrutinized, you did the crime, now it's time to do the time. Suck it up!
And as for eridani's case, ummmm, dude, Obama has been President since January, 2009, nearly 7 years. He didn't commute your sentence, and he hasn't pardoned you. He's your guy, so,