gundar: It's watered down because you can get killed by 12v - I work for a company that makes electric fences, we have to build protection in to our products for this reason.
That's true. Fire risk is also a factor with 12V. I'm aware this is not your main point, but the actual risk of an incident involving probability of death occurring from 240V is much higher. Also there are very strong legal requirements for working with 240V.
Edit: I was wrong. There are legal requirements for working with 12V.