One of the most infamous and prolific train writing crews worldwide celebrates 20 years of mayhem. In 1991, four teenagers from Copenhagen decided to start what was soon to become the biggest graffiti crew in Denmark - Monsters of Art. They have since expanded internationally and boast 50 members worldwide. They are not only writers to watch, but also some of the most wanted by transit authorities - and these are their classic stories from the train yard, complete with daring escapes and not-so-forgiving busts.