I don't know why he should have to explain himself. People take photos of buildings all the time. If the police are going to be moving into this course of action with every bugger wanting a holiday snap they're going to need those £30 officers Abbott has promised.
Following this line of thinking to a possibly slightly illogical conclusion: do we really want to have police spending their time questioning 30 Chinese tourists about why they're taking photos of the Pavilion?