Myth-Busted: Flawed Free Energy from power lines experiment. The experiment proved that these guys really don't know what they are talking about.
People are routinely arrested for 'stealing' electricity using this method. It's called inductive coupling and unless these 'myth' fools know anything about tuning coils and actually grounding the circuit they might aswell have put a wet piece of string in the air.
There was a recent news story about 1301 glowing fluorescent tubes, powered only by electromagnetic fields produced by overhead powerlines display in an English field. (Google: Richard Box Field)