Private security companies have started “pushing the boundaries” of frontline law enforcement and are becoming involved in highly charged areas such as the policing of protests... G4S…has provided mobile custody cells and detention officers at two recent environmental demonstrations...G4S estimates it could quadruple its revenues from policing activities within the next few years, but such a rapid expansion would worry civil rights campaigners. Shami Chakrabarti, director of Liberty, said there were “considerable legal, constitutional and public confidence issues when what many of us see as core policing duties are farmed out to unaccountable private security firms”. [also refers to Reliance Security Group]