The article was thinking of was the second that Stoner posted.
GrahamS – sorry, my point was perhaps not too clear, I wasn't suggesting they arrested him for taking pics of police officers – the guy from harry potter was initally arrested for this though.
From the links posted by Stoner the officers shouldn't have demanded to see his pictures/camera equipment/arrested him unless they had due cause to suspect that he was plotting a terrorist atrocity, seems unlikely against Mick's Plaice
Totally insane, particularly as I spent a happy afternoon in london a few years back taking pics of various landmarks and some amusing ones of armed police outside horseguards who were only too pleased to pose for pics with visiting kids!