We got the following quote from: http://bit.ly/5Y3qkM

“Mail theft is a federal crime,” warned Renee Focht, a postal inspector and spokeswoman for the U.S. Postal Inspectors, a crime-fighting unit of the U.S. Postal Service.
She advises people to not leave mail — especially negotiable documents such as checks and money orders — in their mailboxes to be picked up by the postal carrier.
“Postal collection boxes provide more security because they’re locked,” Focht said.