I live in the US, and I have a "large" amount of property that is clearly marked for no-trespassing. The reason for this is the prior landowner was forced to sell when a trespasser drowned in the pond on the property and the landowner was sued, successfully, by their family.
If there were clear laws regarding trespassers and liability, I would gladly take the no trespassing signs down. I don't care if someone wants to go swim or fish on the very nice pond we have, but I absolutely will not lose my house for someone I don't know.
In the US, at least for most states I'm aware of, the attractive nuisance doctrine applies. And almost anything can be considered an attractive nuisance. It just sucks for everyone because it means the public and property owners lose out.
From my reading, the attractive nuisance doctrine applies to children - who I would have thought would be the people least likely to pay attention to "No Trespassing" signs?
That doesn't negate the parent point, and it's not just about attractive nuisance, although childproofing 100 acres is a ridiculous task. There's also been successful suits from people who get injured after breaking and entering locked buildings
All of the suits of this type that I'm aware of have been pretty well misrepresented by the media or person telling the story. Generally they fall into a couple of categories:
1) The person injured was a child (usually omitted from the story).
2) The owner of the building knowingly set a dangerous trap for intruders (e.g: a shotgun pointed at the front door).
3) Ended in settlement with no admission of wrongdoing by any party.
4) Totally made up.
E.g: the popular "A burglar fell through a skylight and broke his ankle" story was actually a teenager, who climbed on the roof of his school to try to point a floodlight at the basketball court, and fell through a skylight, becoming permanently disabled. They settled out of court.
If there were clear laws regarding trespassers and liability, I would gladly take the no trespassing signs down. I don't care if someone wants to go swim or fish on the very nice pond we have, but I absolutely will not lose my house for someone I don't know.