Meadows Marathon Busking.

I'm realising that my problems with photos of myself are now limiting my photos of other people. I was running late for the Busk and so didn't get photos of the marathon when it started (the runners were really spread out by the time I got there. I did however get some photos of us preparing for the busk (though a lot of them are really grainy, don't know what went wrong there).

However I now have the problem that I look at them and think, if it were me on the photo, would I be happy with someone putting it up online?

Those of you that regularly post up photos of people, firstly how do you manage to take their pictures without either them noticing or getting annoyed and secondly, do you ever have any reservations about posting them up?