zug55 wrote:
As others point out, laws vary greatly from country to country. There also is an ethical issue. I don't see a problem if you photograph a street with some people, as long as individuals do not become the main focus. If I take a picture of people specifically I am simply asking people for their permission. I find that most people are okay with that if you talk to them respectfully, and I find it easier to talk to people than expected.
That's fine if you want posed shots, and if you ask permission, they will be posed shots rather than candid shots. If street photographers had to ask permission, we would be missing a huge number of the greatest images in the history of photography.