I’ve heard of it. Personally I’d never use it even though I have a great dislike for TV. I find it’s a sneaky passive-aggressive way which doesn’t really “solve” the problem. As well, it’s annoying to both staff and other people, and disrespectful to the owner of the establishment who has chosen to install and use TVs in their premise. If a TV is too loud, ask for it to be turned down, or don’t come to the establishment again. You don’t have the right to cause confusion to others because of your personal preference against television.
I mean, a bar – come on, of COURSE there’s going to be TV there. If you don’t like it, go somewhere else. Airports and hospital waiting rooms also qualify as TV-acceptable places in my mind – TV is the most attractive short term distraction for many people, it makes sense to put them where people will be waiting for a short amount of time. Yes reading a book would be a more productive use of time, but who are you to judge and decide what others choose to do for leisure. And with this TV-B-Gone, that’s exactly what you are doing.