I was sitting around waiting for Battlestar Galactica this evening watching Iron Chef America. I had seen the commercials for tonight's episode, and it looked neat so I set it up to record. Towards the end, when they're going over the iron chef and the challenger's entries a McDonalds logo popped up for a single frame. It was pretty obvious at the time because the screen flashes red, I didn't recognize it instantly as the McDonalds logo when I watched it at full speed. I did notice SOMETHING though, and upon rewinding, sure enough... the Food Network is running subliminal advertisements.
So if you start barking at your TV for no reason it might be because the networks are brainwashing you. Or because you're insane. Check to see if you're microwaving your shampoo to make sure.