In 2015 Hong Kong's Face of Litter campaign used DNA samples taken from street litter and collected from volunteers to create facial images that were then posted on billboards across the city. The campaign, conceived by PR firm Ogilvy & Mather and organised by online magazine Ecozine and the Nature Conservancy, was intended to give a face to anonymous Hong Kong litterbugs and raise awareness of the extent of littering in the city and encourage people to…