Reminds me of when I was living in The Hague, there was a "writer's week" or something, and my missus being a writer wanted to go to some things. There was a live radio-broadcast happening from the back room of a restaurant so we went to that. Right up the back, 10m or so from the presenters.
And, as my missus is doing a PhD in writing, she started taking notes on the people and situation and all that. But she didn't have a pen and paper, so she was taking notes using her phone. Not one of those idiots who leaves the 'beep' on when you press a keypad, otherwise silent. But this lady next to her got annoyed, *from the sound of the tactile keys being pressed*. OK, it wasn't a fancy touchscreen, it was a cheap nokia, but it wasn't making that much noise. This lady proceeded to swear and tell her off in dutch (which i could understand but my missus had no idea at the time), all in a lot louder voice than the keys were making, I even noticed an annoyed look from the radio-presenters up the front of the room (at the lady, not us).
Sometimes you just can't win with anybody.

I've never had a problem with photography though, either at gigs or restaurants, from me or others taking photos. It's more the results of those photos, like people posting endless shots on their FB of what they had for dinner last night. I can understand if you made it yourself and you're rather proud of it (hell, i've even done that), but just a bowl of faceless noodles is pointless.

Actually, the only problem i've ever had with my camera was last weekend, I got a photo of a 4wd parked across 2 parking spaces, as they tend to do around here because 4wd owners just don't know how to drive. I had my eos 3 and 40mm in the car, so i got a shot of it. I put it back in my car, then went off shopping. Got 5m down the road and some guy started yelling at me "did you get a good shot of my car?". He had two young boys and was carrying a case of wine, so I just yelled back "no, my car" and made a slightly quick getaway. Don't know why I should feel guilty, he was the dick who was illegally and shoddily parked. Normally I'd just develop the film and scan it and be done with it, but because he was so rude I might just post a copy to the cops for fun...