Mother London really wants you to stop carrying plastic bags, and the ad firm will shame you into compliance if necessary. Their yellow Uncarriable Carrier Bags are overlaid with pictures of objects that you wouldn’t want strangers on the street--let alone your own mama--to see you with: sex toys, drug paraphernalia, and an assortment of weapons. The objects appear x-ray style at the bottom of each bag, sort of like they do in airport security machines. But don’t make the mistake of taking one of these Uncarriables on your next flight; you’ll likely end up arrested.
The bags may defeat the purpose (discouraging plastic bag use) as they’re sort of covetable. Just like Mother’s last round of Uncarriables, which featured bags emblazoned with things like "Tourette’s Syndrome Rehabilitation Center" and the "Phil Collins Unofficial Fan Club." See those here.