Yes, I can see your point Clive. But I don't think that this would realistically be an issue. I doubt very much whether a potential thief would sit on our forum all day on the off chance that someone MAY mention that they're going on holiday, or have a security problem, and MAY give the area that they live in, and MAY actually turn out to be local to them. After all, a local thief is more likely to notice a caravan parked on a driveway one day and gone the next, which tends to be a bit of a give away. It doesn't mean that the house is empty though, so they would still have to monitor it for occupancy. And why would a thief bother driving a long way to an unknown address just because the owners say they are away? There may not be anything there worth taking, or security may be so high that they can't get in. Walking down a street at night and spotting houses in darkness is an easier way to do it. As for caravan security, well, judging by the letters that appear in mags and the forum, I don't think that it really matters if security devices are fitted or not. Come the end of the day if a thief wants it, he'll take it regardless. They are really only going to stop an opportunist who's driving by and fancies his chances. Most caravans are stolen to order anyway, so they're more likely to drive around until they find what they want and then return in the small hours.
You point is valid Clive, but I don't personally think that it's likely to be a problem.
There are obviously arguments both ways, but several sites have forums where full names are used, and as far as I know by it doesn't present a problem. As you say though, it's irrelevant now anyway.