I saw one in the central part of Berlin (admittedly close to a big park) one evening a few years ago and also a few in smaller towns where I lived before. Also I remember news-stories about a racoon living near Alexanderplatz - quite at the center of the city (don`t know if the stories are true tough. Racoons ar not native to Germany but it looks like that some escaping from zoos etc. were quite successful in surviving). Never heard of any remarkable problems with either of those living in town.

Different thing with the wild boars that slowly move in to the outskirts...saw a few (mother with piglets) at a public transport station last year. Since they live in families they can be dangerous when they feel attacked.