Is it legal for a customer to use a TV-B-Gone to turn off TVs in businesses, e.g. the ones playing sports channels in restaurants or the demo models in stores, without permission of the owner?
Trespass to chattel
The TV is owned by the store or restaurant. You are not allowed to use it or manipulate it. So you commit Trespass to Chattel, which is "the use of property without permission of the owner" and a common law tort. To prove Trespass the store would need to show:
- You intended the trespass on the chattel, in this case, by turning off the TV. That can be proven by you owning the TV-B-Gone and using it.
- You deprived the owner's use of the chattel for a substantial time, which in the case of a sports bar might be any moment of the game, especially if the bar is allowed to run sports bets.
- in the case of the sports bet bar, you might even have created harm to something that the bar has a legitimate interest in.
The Sports Bar might have the much easier case, while the store might not be able to prove the required deprivation of the chattel or damage caused by turning it off. Similarly, if a TV-B-Gone turns off a public CNN monitor at an airport though, you created harm because CNN would need to send a technician to turn it on again - the remote controls are only with the technicians, not in place. Do note that because of TV-B-Gones many such displays are installed in shielded boxes, or have been modified to not register to remote controls at all. Most sports bars don't even have a TV there, it's a computer monitor that is fed from a stream.
However, if it's store advertisements... I doubt you turning it off would have caused the substantial deprivation to qualify as trespass to chattel. And while TV-B-Gone is just a tort... Don't you dare to run a cellphone jammer:
Well, Cell-Phone-B-Gone could be done, but it’s illegal. One way to do it is to create a very low power fake cell transmitter, and the phone call would be gone. But disrupting a cell phone service is illegal in and of itself. - Mitch Altman, inventor of the TV-B-Gone in a 2006 interview