“Whereas in the past the police have not had the power to prevent photographs being taken of them, from today they have. Under the new Counter-Terrorism Act it is an offence to take pictures of officers “likely to be useful to a person committing or preparing an act of terrorism”. This is such a catch-all measure that it can be used – and, in view of recent trends, will be used – to prevent photographs to which the police object merely by invoking counter-terrorist requirements.”
(Source)