My sister's friend met Gok Wan in a club in Liverpool one night, and went up to him and said "Hey Gok, sorry to bother you, but what do you think of my outfit?" (or something like that) and he just said "Sorry love it's my day off" and just turned his back on her.
I know he must get it all the time but politeness costs nothing. I was gutted because I love Gok on TV.
But to be fair that is probably as polite as you can be in telling someone it's their day off. I firmly believe that people in the public eye are on duty when working but if off duty then we have no right to approach them.
I have always found west end stars at stage doors extremely accommodating in signing autographs and having piccies taken and same with bands and solo artists but I wouldn't dream of approaching them in the street. Living near London I would often see TV stars/ celebrities etc