(All of the antennas are registered, along with type, propagation, etc, with the FCC, and they produce a large database)
Not that TV signals are great.
But even the bluetooth group itself says not to use beacons:
"According to the Bluetooth Special Interest Group,[24] Bluetooth is all about proximity, not about exact location. Bluetooth was not intended to offer a pinned location like GPS, however is known as a geo-fence or micro-fence solution which makes it an indoor proximity solution, not an indoor positioning solution."