Bristol Mayor Marvin Rees said the council's control centre has face-recognition technology which “could probably track everybody in the city”, as he revealed he wanted to get “more aggressive” on littering.Rees said the security cameras were “phenomenally effective” as he pledged to crack down on what Bristol City Council calls “environmental crimes”.But he alluded to potential legal and moral issues around taking such an approach in preventing littering.The mayor has made it a core pledge of his time in office and civil enforcement officers hired by the council from external company Kingdom have been prolific since being introduced late last year.Littering, spitting, graffiti, fly-tipping, fly-postering and dog fouling can all land you with a £100 fine in Bristol if you are caught by the so-called 'litter police' from Kingdom.In 2015, Bristol installed a $10m surveillance system in order to bring them up to date and provide a more comprehensive approach to security.