There is a lot of nonsense (including most of the above) in relation to private cctv cameras.
In my previous life, I used to engage in a bit of photography, and took the legal position with regards what you could and could not photograph very seriously. Restrictions on what can be photographed are broadly the same as those that can be filmed by a cctv system (after all, the cctv system is just continuous photographing).
Anything which can be viewed in public, can be photographed, with a few very special exceptions, which will not be applicable to most home cctv system. This also applies to what can be seen from your property.
There is nothing to stop you positioning a cctv camera which is trained on your neighbour�s front door, recording each time they come & go. However, they would have a very good case in gaining an injunction stopping you doing this, it being an unreasonable intrusion in their life.
One of my cctv cameras covers my front gate and a significant part of the path way, everyone walking passed is captured on my cctv system. In theory, they (or the authorities) could try to get a court order to stop me doing this. However, I would point out to the court that the cctv camera was there for security purposes, it is also on a continuously over-recording hard disk and only viewed should an incident require � I would expect the court to say this was perfectly acceptable, especially since I have recorded (on the cctv system), damage being committed against my property.