...at the pool...
I was at the local pool for swimming lessons for my kids, 6 out of the 8 days they went. I took along my Mamiya 645 on a monopod and shot a few rolls of my guys.
On three occasions, a different staff member came up and said, "Just so you know, you're allowed to take pictures here as long as they're only of your own kids".
Of course, that was what I was doing. If I'd wanted to take some shots of, say, the lifeguard course going on at the same time, I'd have asked permission. I was, as usual, being careful not to have my camera pointing at any girls' bums while I was not shooting (which paradoxically means that one has to be aware of where all the bums are in order to avoid them....).
So, I'm wondering, since the Mamiya is hardly inconspicuous, could that have been an issue? If I'd taken my little Minox B, would as many staff members have noticed and said anything? No one hears mirror whack from a Minox. Also, you can get a Minox right angle finder for those true spy camera "around the corner" shots.