Yes Paul, this is becoming a big issue, clouded by the increasing anti-terrorism paranoia. You all sorts of stories about people being asked to delete pictures from their cards when they've taken pictures in public places - common sense is starting to go out the window!
I once had to hand my camera in to security before they would let me into Birmingham Indoor Arena a while back as it was deemed 'professional'.

Like you say its probably better to ask when we go anywhere else.