Long ago, before HD, I had east and west coast feeds of the big three networks. (Originally, the east coast CBS feed was my local station (which was also, incidentally, the first HD broadcaster in the US), which was kinda neat, but they changed it to the NY station at some point.) Then, at some point, the local ABC and CBS stations complained, and their feeds were removed, but I kept the NBC. Then, when I got HD, I had the HD feeds of NBC, too. Then someone decided that I was only eligible to receive the east coast HD NBC feed. I don't know what the rules are, but they seem very haphazard.