The use of CCTV, viewing an area outside your own property is a Legal Minefield.
For example: Should you discover who was 'Keying' your car, that person would have a case against you for the invasion of his privacy that was far greater than anything the keying of a car would produce. The fact that this is illogical is neither here nor there.
I drive a Taxi (Hackney Cab) and carry a camera with me as SAC will not allow me to install CCTV. My Lawyer has told me that I have to verbally warn anyone, and have proof that I have done so, that I am about to photograph them and that a Printed Notice is not, at the present, regarded as sufficient warning.