I had a bunch of AltHD (and SD) channels show up a couple days ago. They all appear to be sports channels. A couple of local baseball games were playing, but most said "game is blacked out". I always thought local games were blacked out and out of state games were not... I plan to check most of these stations to not show up in the guide, but would like to keep the ones that actually show something. Is there a way to tell which channels actually broadcast something I can view?