You may have seen one lurking in your neighbourhood. It may have aroused your curiosity; it may even have scared you. The boldly painted patrol cars of private security firms are becoming a distinctive presence in many communities around the UK - and, according to a new study, they reflect our spiralling, and frequently unfounded, fear of crime.

The Royal Institution of Chartered Surveyors (Rics) says in a report out today that the rise of private security firms in residential areas stems from an increasingly polarised society, a trend that has been exacerbated, it says, by the ever-widening extremes of wealth within our cities.