I'm not sure about any regulations here, but I know some people have gotten into trouble for building fences with barbed wire or other similar sharp objects on the top (e.g. burglar tries to climb a 10 ft. fence to break into a place, gets badly cut on the razor wire on the top, then sues the owner for his injuries!
).
This area is rural, 20 miles from the big city, so there's not too much of a problem with security. The only electric fences I've seen are an occasional one to keep livestock in fields. But it's more crops than livestock around here, so even those are few and far between.
[This message has been edited by pauluk (edited 09-12-2003).]