Ditton's provisional findings are that CCTV reduces crime under the lens by around twenty percent - still an impressive figure, but one which might be bettered by more conventional approaches to law enforcement. The report presents evidence that the technique is less effective than was first imagined, and that the impact on crime is patchy. The crime statistics rarely, if ever, reflect the hypothesis that CCTV merely displaces criminal activity to areas outside the range of the cameras. One of the features of current surveillance practice is that the cameras are often installed in high-rent commercial areas. Crime may be merely pushed from high value commercial areas into low rent residential areas.
Councils often find that it is impossible to resist demands for such systems.
Originally installed to deter burglary, assault and car theft, in practice most camera systems have been used to combat what town officials call ''anti-social behavior,'' including many such minor offences as littering, urinating in public, traffic violations, fighting, obstruction, drunkenness, and evading meters in town parking lots. They have also been widely used to intervene in other undesirable behaviour such as underage smoking and a variety of public order transgressions. According to a Home Office promotional booklet, CCTV can be a solution for such problems as vandalism, drug use, drunkenness, racial harassment, sexual harassment, loitering and disorderly behaviour. Other innovative uses are constantly being discovered. The cameras are particularly effective in detecting people using marijuana and other substances.