The first CCTV cameras used in public spaces were crude, conspicuous, low definition black and white systems without the ability to zoom or pan. Modern CCTV cameras use small high definition colour cameras that can not only focus to resolve minute detail, but by linking the control of the cameras to a computer, objects can be tracked semi-automatically. For example, they can track movement across a scene where there should be no movement, or they can lock onto a single object in a busy environment and follow it. Being computerised, this tracking process can also work between cameras.
The implementation of automatic number plate recognition produces a potential source of information on the location of persons or groups.
There is no technological limitation preventing a network of such cameras from tracking the movement of individuals. Reports have also been made of plate recognition misreading numbers leading to the billing of the entirely wrong people.[17]
CCTV critics see the most disturbing extension to this technology as the recognition of faces from high-definition CCTV images. This could determine a persons identity without alerting him that his identity is being checked and logged. The systems can check many thousands of faces in a database in under a second. The combination of CCTV and facial recognition has been tried as a form of mass surveillance, but has been ineffective because of the low discriminating power of facial recognition technology and the very high number of false positives generated. This type of system has been proposed to compare faces at airports and seaports with those of suspected terrorists or other undesirable entrants.
Computerized monitoring of CCTV images is under development, so that a human CCTV operator does not have to endlessly look at all the screens, allowing an operator to observe many more CCTV cameras. These systems do not observe people directly. Instead they track their behaviour by looking for particular types of body movement behavior, or particular types of clothing or baggage. The theory behind this is that in public spaces people behave in predictable ways. People who are not part of the 'crowd', for example car thieves, do not behave in the same way. The computer can identify their movements, and alert the operator that they are acting out of the ordinary. Recently in the latter part of 2006, news reports on UK television brought to light new technology developed which uses microphones in conjunction with CCTV. If a person is observed to be shouting in an aggressive manner (i.e., provoking a fight), the camera can automatically zoom in and pinpoint the individual and alert a camera operator. Of course this then lead to the discussion that the technology can also be used to eavesdrop and record private conversations from a reasonable distance (e.g., 100 metres or about 330 feet).
The same type of system can track an identified individual as they move through the area covered by CCTV. This is being developed in the USA as part of the project co-funded by the US Defense Advanced Research Projects Agency. With software tools, the system will be able to develop three-dimensional models of an area and track/monitor the movement of objects within it.
To many, the development of CCTV in public areas, linked to computer databases of people's pictures and identity, presents a serious breach of civil liberties. Critics fear the possibility that one would not be able to meet anonymously in a public place or drive and walk anonymously around a city. Demonstrations or assemblies in public places could be affected as the state would be able to collate lists of those leading them, taking part, or even just talking with protesters in the street