Watch a report by ITV News Anglia's Matthew Hudson
A team of amateur detectives are tracking down stolen bikes in Cambridge. Omar Terywall said he was "fed up" seeing cycles going missing in the city, so decided to set up a facebook group where people would post tip offs and track down missing bikes on online sales pages.
So far more than one hundred bikes have been returned to their owners since the site launched fifteen months ago.
Police say people should still formally report bike thefts to them.