I am a professional Photographer and at least here in Germany its plain simple. Taking Photos against someones will is kinda illegal and considered stalking basically. Private People own the rights on their own pictures automatically. People in Parades are not private People and for them its clear when they start that people might take pictures. Roughly spoken those Streetshots where u take pics of women from behin are really (a mild) kind of stalking...

On the other Hand, you would be surprised how much women allow you to take their pics if you ask them nicely in the spring or summertime in the park and even start posing like pro´s for your camera.

I have a big collection wich i can use inside my photo-store for advertising, but even those women allowed me to take their pictures i am still not allowed to show them anywhere else without their permission.

But i guess you got the point : Those "common" Streetshot are basically stalking. I doubt some women will go and sue someone, but only because they cant find out who took em. A Webpage can get in major trouble if they get sued for showing pics without permissin IF someone finds out, because a websites holder is responsible for what they offer.