Check you local bylaws, carpet gripper, razor wire on fences or glass on walls must be inside your property and above 2m to protect the public and that includes your friends, family and visitors welcome or unwelcome. Rules/laws and rights are in place to protect us all and sadly it errs on the side of the ones that manipulate them the most.
CCTV cannot capture or record public property or others private property without a licence or permission if you are hoping that the police would act on it
I remember a case where the council applied vandal grease/paint to drainpipes and the thug slipped and injured himself and managed to sue the council as there was not adequate if any signs posted warning him :-/
Crazy but true :(