Just found this and wondered what the mumsnetter consensus is.
(attempting link)
www.independent.co.uk/news/uk/crime/officers-claim-they-dont-need-law-to-stop-photographer-taking-pi ctures-2012827.html
Basically, it is a 16 year old freelancer photographer, who is taking photos at a parade. He gets stopped by the police and amongst other things is told it is illegal to take photos of minors without parental consent, it is illegal to take photos of a police officer, and he is considered a threat under the Terrorism Act.
There is a recording of altercation with the police. Personally, I think he was in the right, and it is good to see a young person willing to stand up for themselves. However, endless repeats of 'under what law...?' may not be the least antagonistic way of going about things - but, he is 16! The confusion surrounding the laws on photgraphy need to be clarified, although as the Chief of Police Officers have already issued several briefings to police forces explaining current laws, I am not sure what else can be done.