Different places around the world have different laws about photography.
In USA and Australia I am pretty much free to photograph what I want (within reason, of course) if my subject is in a public space; however, I can not freely walk into a private property and photograph to my heart content. I understand.
Recently I was in Europe, Austria specifically. I was made aware that photography in a public place is restricted. I have heard of copyright laws forbidding individuals photographing certain buildings (The Eiffel Tower apparently is one of them) but I didn't know I was not allowed to take pictures of people in the street. To be more exact: I am not allowed to publish those images, or print them for public display, without a written consent.
Of course I laugh at such pitiful laws that seem to have been written without much thought or consultation and currently totally unenforceable. To the millions of images taken by the public every day with mobile phones in the street I say: keep on snapping, exercise your right :-)
Salzburg, Austria. Zuiko14-42mm EZ f5.6
But to the concerned photographer (not me) that wants to stick to the right side of the law, what is there to do? Get a signed released from every person depicted in his/her images? yeah, right...
Then it occurred to me: how does the law apply to images published electronically? the law does not say one can not take the photograph, it says about publication.
What if the publication is not in Austria? what if it is published for an international audience? what if the server to where those images are uploaded to sits outside Austria?