Originally Posted by KenF

For the UK, pretty much anything that is on, or (subject to some common sense exceptions) visible from public land is fair game - there is no "expectation of privacy" in a public place, and, contrary to popular belief, any argument that hinges on copyright is doomed to failure (copyright in an image rests with the photographer, not the subject). Even on private property, you are entitled to assume that you can photograph what you want unless previously advised otherwise - you only start to risk "committing an offence" if you fail to stop when asked (and, the above German precedents notwithstanding, if you attempt to grab someone's camera or force them to delete photos, you are very likely to be guilty of an assault).