Is that a cultural difference, such that the UK tone for "proceed and you may die" takes for granted (with, presumably, support from their legal system) that the reader is at fault if they ignore the phrasing used? The US is particularly vulnerable to lawsuits seeking vengeance, and spends a lot of time agonizing over phrasing that is defensible against both literate and illiterate people. So it could be possible that the phrasing is correct for the UK, but not for the US. I'm not sure, though!
I don't know about UK-US, but I think I've noticed a difference between the UK and Germany in this respect: in the UK the sign tells people that something is dangerous and gives some hint of why; in Germany it just says "Verboten" with no mention of the danger, which in the UK would seem to be highly negligent and asking for legal trouble.
Something that injures a burglar could equally well injure a police officer, a fire fighter, a representative of the water company, ... it's amazing how many people can legally enter private property without the owner's permission. Of course one should be allowed to assume that such uninvited visitors are cautious professionals so you don't have to make everything childproof, but if you're aware of a serious danger yet can't be bothered to put up a warning sign ... you'd better have good insurance.
"it's amazing how many people can legally enter private property without the owner's permission"
Scotland has 'right to roam' so we can wander about pretty much anywhere (with a few sensible restrictions) and there are actually very few signs at dangerous spots - I can only think of a handful. The idea that you would go onto someone else's land, have an accident and then blame the landowner seems a very strange idea to me.
The legal system of common law and tort is pretty similar. The _culture_, on the other hand, is very different; no culture of "ambulance-chasing" (although in recent years it's been seen for road accidents, pushing up the price of everyone's insurance). No history of huge damages awards for trivial things. Not the same anti-government culture; the stream is probably owned by the local council or the waterways authority.
It's human nature to (1) distrust authority, (2) assume that authority is generally more nannying and risk-averse than you yourself are, and (3) want explanations consistent with your understanding of how the world works.
Human nature would like to disagree with you about the nature of human nature.
;)
I bet a dollar that the environment - nurture, as opposed to nature - will have a huge impact on a persons attitudes and beliefs and behavior towards authority.
Imho vast claims about human nature should be backed up with some scientific or well-sourced evidence :).
I wonder about the second point. Is it human nature or a learned reaction we have because in our lives we experience authority as overly- cautious? First our parents, then our teachers, then the government (perhaps less so, depending where we live) are constantly telling us not to do things because they're dangerous even when odds of injury are relatively low.
