magnetic yellow card.

»This magnet was tossed onto your car by a cyclist who felt that you might have been driving in a way that could have endangered their life.«

in vienna, most people carry out their mental troubles (which are aplenty in freud's homebase) in everyday traffic, especially in cars. that's why each pedestrian needs such a yellow card, too, since car drivers are totally ingorant of crosswalks. (do they teach this in driving schools?)