Honestly I think it depends on where you live and how tight the mail and check cashing systems are. Regardless of how it occurs though, if you have a check stolen and cashed it can be traced although its a big hassle. People who do things like that are lame and ignorant.
When I lived in New Orleans, it was a huge difference being from Los Angeles. The first month living there most of my mail was lost or stolen. All of my new bank account checks, atm cards, nowhere to be found.
Then my upstairs neighbors all of a sudden were jamming the entire Public Enemy cd catalog which Fletch and I had just mail ordered a week or two before, so it was pretty evident what had happened.
We just let it go so as to not start shit and moved soon after.
And once I got a bundle of mail in my box that was post marked like two months previous. I think my mail man was on crack.