To Cleeds,
You said above "
because a fault on the ground wouldn’t trip the breaker back at the panel"
What I said was ANYONE WHO DIDN'T KNOW ANY BETTER would think that the breaker would never trip. All we are talking about here is a piece of audio equipment that's chassis has become energized, and is sending current to an illegal exterior grounding rod. Why is the equipment dangerous if it's sending the current to the illegal grounding rod, unless you are standing barefoot in water while playing your stereo, and then you become the ground? Please don't go to your NEC code book for the answer. It's the grounding rod that is the real danger, because lightning makes it a fire hazard.
On Feb. 16th I wrote above that an electrician in my club had his drapes catch on fire from lightning hitting his illegal grounding rod, for his stereo system, and that is when I pulled my illegal grounding cable out of my house. If that electricians house would have burned down an insurance adjuster would not have paid the claim. Insurance companies will not pay off for any work done to a house without an building permit, and that goes for house additions too. County governments keep accurate records of building permits all the way back to when the house was built, and the adjuster will check them before he comes to your house.
In older homes there are countless pieces of equipment that do not have chassis grounds. As I'm writing this I'm also playing my stereo that has a phono section, a line preamp and dual mono power amps that all have switches to lift the chassis grounds. Those mono amps always play with the ground lifting switches in the lift position, because they sound better that way, in my system that has extremely sensitive speakers. Even if those chassis became energized they would have to stay that way as long as the sound remained better.