The NYC subway system is a home away from home for most New Yorkers, and though the good people of MoMA have done a pretty good job brightening our time underground with their new modern classics posters, Poster Boy has taken it a step further and made walking around in a smelly, crowded tunnel even more interesting. The artist/vandal is back again this week, bombing MoMA's most expensive subway ad-art campaign ever, possibly complicit with MoMA and against the wishes of the campaign's installers CBS Outdoors. However that ends up, you can watch Poster Boy do some stuff on video after the jump.