Comment by simoncarter

Photographers being detained seems to be an unfortunately frequent occurrence in London (anecdotal belief rather than based on any numbers). There are a number of videos on youtube of people having filmed themselves being detained for the same or similar reasons. It is tricky issue; you want to prevent terrorists gaining information on the security measures of certain buildings/areas, while allowing non violent citizens to go about their day. However I fear if terrorists were to do this, they would be more subtle, using hidden cameras, or working off memory and multiple trips, so seems like the current approach only impacts genuine photographers and concerned citizens. Usually, looking at the videos on youtube, the most unsettling part is the behaviour of the security guards and police officers, though I do seem to remember one video where the police officer/PCSO was reasonable.