LOL.That's just not true. It might be the case for some city centres, but not elsewhere.
Also, those CCTV networks are not joined up - the majority of them are private, and only small scale.
The GCHQ is definitely tapped into those. They work hand in glove with the NSA, and the NSA has tapped just about every major transmission line on the planet.
I'm not saying we've got some stooge watching you on a screen everyday, but it should just be treated as plain fact that the world is bugged now.