This is an article published in the UK. The law in other countries may well be somewhat different, but that's for you to find out. I take a fair few images of people out and about; in these days of fear of stalkers, terrorists and so on I think it's important for photographers to know what is allowed and what is not. Know your rights before you shoot.
Here's the article: http://www.digitalcameraworld.com/20...ltimate-guide/
