Out of state license plate and visiting a post office in Colorado? I'd bet that whatever you mailed to your home address would have a great chance of being intercepted en route.
We can all create conspiracies here, but that wouldn't fly over the fourth admenment.
However the US post office uses an automatic scanner system to read packages. I cannot imagine the NSA, with its insane desire for meta data hasn't tapped into it yet.
They may have added the functionality by now, but when I worked on the system, it only encoded the destination address.
They don't take pictures of the mail for fun or for tracking, it's purely for sorting. You want all the mail in a letter carriers truck to go into the truck in the order it's going to be delivered in for efficiency.
So the system was in one of two modes, destination address coding or return address coding. Which mode it was in was determined by the mail processing plant itself.
Also, it only photographed letters that did not have a presorted barcode printed on them. If it already had a barcode it just got sorted immediately.
I'm not sure what there really is to tap into here.
