OSM has implemented a feedback tool for its map not unlike ArticleFeedback (allowing for anonymous submission):
http://blog.openstreetmap.org/2013/04/29/openstreetmap-opens-up-to-more-cont...
It's not as prominent which mitigates the noise somewhat, but I'm seeing a few spammy notes already, as well. ;) To see notes you have to have the "Browse Notes" checkbox ticked in the Layers icon (top right corner), and to add notes you have to click the tiny "Add a note" link in the bottom right.
-- Erik Möller VP of Engineering and Product Development, Wikimedia Foundation