Watch this footage taken by Guardian journalist Paul Lewis during his standoff with City of London police outside a famous London landmark.
Assistant Commissioner John Yates, the senior Metropolitan police officer leading Britain's fight against terrorism, has warned that police risk losing public support by abusing anti-terrorism stop-and-search powers when dealing with people taking photographs outside public buildings.
Urging officers to use common sense, he said photographers should not be stopped and searched unless there was a "very good reason".
His formal message to officers follows an increasing number of complaints from amateur and professional photographers, who stated they were being stopped and questioned without reason by police and security guards under anti-terrorism laws, on suspicion of being terrorists on a "hosile reconnaissance mission".
Yates said that while police should remain vigilant there was no restriction on people taking photographs of public buildings other than in "very exceptional circumstances".
He also added that there was no ban on photographing front-line uniform staff and the act of taking a photograph in itself was "not usually sufficient to carry out a stop". He added: "These are important yet intrusive powers. We risk losing public support when they are used in circumstances most reasonable people would consider inappropriate."
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