English essay about CCTV cameras

An integral part of today's life are thousands of CCTV (Close Circuit TV) cameras, which monitor our every move. They watch us from building entrances, traffic lights, train stations, in the underground system, on buses and hopefully not yet on public toilets. They're supposed to help fight crime, and they certainly do help a great deal, but are we, or, better to say the authorities, getting the maximum benefit from them? And is it really correct to record our steps 24/7? What about privacy? And what about the potential misuse for someone's own profit, a blackmailer for example?
There certainly are strong arguments in favor of CCTV, forcing us to obey traffic rules for a start (or the council's pocket in case of not obeying). CCTV also helps the police to solve crimes, mostly by identifying the felon, as in the murder of an 11-year old boy from Liverpool this summer. But not all that glimmers is gold.
Although the knowledge of being watched by police officers 24/7 should make us feel safe and sound, it is not the case, and there are quite a few reasons. Firstly, most CCTV systems belong to private subjects and the police does not have access to them. Secondly, with over fifty thousand cameras just in London it is technically impossible to watch every single one in real-time and intervene immediately in case of a crime. Hence it is obvious that the tapes are being used only if the felony has already happened and requires investigation, thus serving as proof and not as prevention. It is also necessary to mention that there is often no interest in CCTV records, either for lack of initiative (bus drivers) or due to technical imperfection (black and white screen, lack of audio). Finally, even the most advanced camera can be smashed by a stone or a bullet.
CCTV is indeed a great invention which serves its purpose, but it could and should be used more effectively. Instead of deploying thousands of cameras on every corner, they ought to be fewer, but technically more advanced and better controlled.