Does that really work? The SSID is included visibly in the traffic frames. Anyone capable of setting up an access point to overpower the signal and hijack client connections is going to also be perfectly capable of popping the SSID out of the frames being sprayed through through the air.

If it's a competing ISP stealing customer connections then your dealing with a legal issue ultimately. It would be no different than someone sitting beside the local coffee shop running a rogue access point to MITM the customers.