aemeijers wrote:

Just make sure they have a soft place to land, like grass, when they
do their face plant. Trip wires that just make noise as the cord
breaks are one thing- trip wires (or neck wires) that cause injury
are likely to involve civil and criminal liability. Yes, even on
private property, if not in an enclosed area. Law and case law
recognizes that LITTLE kids, livestock, etc, wander at times and have
to be retrieved, and that others (say, a cop chasing the kid
vandalizing a neighbor's house) may be injured by your booby traps.
If you want a perimeter wire, I recommend fishing line attached to
tin cans full of ball bearings, balanced on a rock. It'll make a
racket, but nobody will get hurt. And it is a lot cheaper than
parachute cord.

Right. That's why booby-traps are illegal in every jurisdiction.

Any number of people can enter your property without permission (or even
knowledge). You've mentioned a couple (kids, livestock), but the list
includes civil trespassers (a hobo trying to keep warm), the postman, a
fireman, a peace officer with a valid warrant, meter readers or utility
repairmen, salesmen, even Jehovah's Witnesses.