I will put this argument to rest. at rest, the line has the stated DC voltage constantly there. something from 40-70 VDC. when someone calls your land line, the system sends a ringing pulse int he form of 120VAC, but very low amperage, so there is no risk of the wires "frying". This does not mean that the DC voltage is interrupted at all. You can send two different currents over the same wire. Your electric company does this all the time to send information either from your meter to them(if you have the electronic thing on the meter) or between substations or plants. Now if you simply connected a 48V light bulb, it would stay on steady until someone called you. Then it would either pulse from it's normal brightness to really bright and stop when it stopped ringing, or it will burn out. This is where the guy in the video got the idea for the voltage regulator and bridge rectifier from. It will not allow it to damage anything you connect to your phone jack for power usage as long as it's between the appliance and the actual phone line. No it won't power much as far as appliances go, but it would power a radio, a bunch of led lights(think rope light) or even a small tv if you knew what you were doing. Also, the only risk of melting wires you have is in your home, as the ones the tel company uses are quite robust for what is running through them. Illegal? i doubt it, if they are dumb enough to leave lines connected on your home, which is your property, then it's the equivalent of leaving your wallet on the sidewalk, and expecting it to stay there, and then calling someone who found it a thief. As earlier stated, there are safeguards in place to keep a steady current draw on the line. Not sure if that is to save their battery, or to keep open lines in fact open. either way unless you try it with a simple bulb, you'd never know. just be careful. To each his own I say.