>Why people on forums cannot disagree without resorting to personal offence is beyond my understanding.

Perhaps because that's the only time you bother to give any response... I've posted a couple of serious, inoffensive replies to you now and you don't seem in the least bit interested...

The consensus view seems to be that a sign should be put up, you don't agree but have only given the vaguest of reasons why. I think, on the whole, most of us would rather sites didn't need to have signs, but if a sign is all it takes to lessen the possibility of damage, where's the problem?