Just thought I would add a few thoughts on the subject.
As a casual shooter I am very conscious of not offending and getting in people's faces to get a good photo. Especially since I am not getting money, why bother people and risk a confrontation. Even around family I am selective when I take a picture. I don't want to be so focused on getting a good shot that I miss the fun, or get in the way.
That being said when I go to an event such as a carnival or a renaissance fair I am a little less shy when taking a picture. If you dress up, don't be shocked when I snap a picture.
Carnivals, renn faires, festivals or whatnot where others gather and interact, people expect to have their photo taken. This weekend we went to ren faire and my husband was wearing his Ale Mail.. you got it, plate mail of beer bottle bottle tops. We got stopped over and over so that people could compliment, talk to,
touch it [yes they were petting his scales and picking at them] and photograph him. After several hours it got kinda old but he wasn't upset about it, he wore it because he thought it was novel and expected a few people to notice. It was way more than a few and he is probably all over the internet now. I am.. not so brave and yet during the zombie walk last year I was photographed by people. I was a zombie hunter. I am sure my face, with gas mask and without.. is out there too. I don't feel I am very photogenic so I try to avoid the camera.
To return to your point, I have read this debate over and over in different forums (which is not to say that it is not worth repeating). One sticking point often seems to be an obstinate insistence on the part of some photographers that "It's my right to take your photo in a public place and it's your problem if you don't like it, not mine".
A couple years ago at that same fair mentioned above a photographer asked to shoot my daughter, then a minor. He did ask and I did question what he was going to do with them. See at that time I did not nor did I let her post her face on the web. Too many loonies.. but in the end he gave me a card, not that it led me to a site or anything and I let him photograph her. She was in costume, that was his motivation.
Every weekend there is a local meetup of classic and antique cars. Everyone is shooting cars, sometimes shooting people [I photographed a guy that looked like Elvis!] and again because of what is going on people are more accepting. One guy, George, was in one of those mobility scooters and after he teased me, 'did you get me?' I said yeah but I bet you can do better than that.. and then he posed. During events is a good time for new street photographers to shoot because everyone is.
Another instance, Chicago, the bean or Cloud Gate, everyone stands in front of its mirrored surface making faces, playing with their reflection and the reflection of others and taking photos. Went there with my cousin and I was doing it too. I am also sure that I was in several photos though the bean tends to distort things. All good situations to get some interesting shots of people and less likelihood for confrontation.
If doing it makes me feel creepy then I respect that others might feel creeped out by it. And then I don't do it.