some questions

Does anyone know how hard it is to track down and find a illegal transmitter running 500mW into good antenna ?
I do suspect that more transmitted power makes it easer to find a transmitter.

Has anyone tried to "fox hunt " ?
http://en.wikipedia.org/wiki/Transmitter_hunting

I also wanna know how often transmitters are stopped in customs.

The maximum legal Effective Radiated Power on mp3 senders are 50 nW (87,5 - 108 MHz) here in Norway.
The confusing is that another rule says that 2,5 micro watts is the power limit for a non licensed transmitter.