It's only wrong if the reason for taking the photos is wrong.
Neither the girl or her dad (I presume her dad, was the adult with her) seemed to care. They both saw the three of us walking the main paths taking their picture ( we were quite noticable), and they didnt give us a second glance.
Neither did the guy on the jetty who was talking on his phone and smiled at me just before I took his picture, nor did the old man on the bench, nor did the old lady as the toddler next to her threw another piece of bread at the geese, nor did the woman who leant down to give her son something then turned and looked straight at me as I was taking their picture, then went back to her breadgiving - quite clearly unbothered.... Nor did the grandfather/father/son trio. None of them cared in the slightest.
There were some who didnt notice me and some who did (it's shocking how many people can see you when you arent hiding in the bushes....
).
Of those that did, none took more than a half seconds notice, and (amazingly considering all the violent people in here! 
) not one single disgruntled parent came over, took my camera and threw it in the lake after breaking my jaw.
If they didn't take any offense then who are you to take it on their behalf?
Exactly right.
I have taken possibly thousands of pictures at various swimming comps over the years, and I have ever had one single person come up to me directly, or even heard of anyone indirectly complaining of pictures being taken of their kids. I have also taken loads of pics of people going about their daily business, if a situation seems worthy of a picture to capture that moment for posterity, I will take that picture without a second thought for who may complain, if someone does then I will happily delete the picture, but no-one ever has.
I personally believe that there is a lot of people on here that are over reacting to a non event.
I am a father and if I had ever noticed any one taking pics of us, I may ask to see the pics, and would probably ask for copies if they are any good, but that would be as far as it goes, I would never resort to violence (it solves nothing).
If you are out and about and trying to capture moments like this, and you are about to press the shutter but you have to stop to think, ohh, who is in the picture, who are the parents of any kids about, who may complain if I take this picture, what if this, what if that, then most likely you will miss the picture you first saw and intended to capture.
That is the whole esscence of candids, they are spur of the moment, instant captures of a moment that may never happen again, the capture of an expression, an incident, and event, that cannot be staged or recreated, (if you try, you take away the whole spontineity of the moment).
If you have to stop and think before pressing the shutter, you may as well pack up all your gear and sell it on fleabay because the whole excitement of capturiing that instant will be taken out of the equation.
