Planning a trip to Europe next month.

I heard that a new law in England, subjects photographers to possible police detention and questioning. Also the photographer has no rights.
If the police think that photos of Police Officers or Military Personel, or buildings, may be used by Terrorists, The Photographer may be held without counsel for indefinite periods of time.
Does this mean I can't photograph the changing of the Guard at Buckingham Palace, or the Double Deck buses, Big Ben, Trafalger Square ?

Should I just stay out of England?