After that last image, mine hardly compares. I started seeing all kinds of crazy stuff in a nearby town, including someone gone mad with landmarks:
Note that this is after I deleted nearly a hundred parking lot segments, each only a few tens of feet in length, none connected to any other road.
I did my duty and sent the offending user a polite and helpful PM about editing basics. He claims his little kid got on and did all the editing. Talk about a baby Wazer!
There must be hours and hours of work he put in to drawing and labeling every little business in this town, and drawing unconnected parking lot roads, and making roundabouts for dead end streets. The little tyke must not have known about the undo feature, either, because some of these are landmarks upon landmarks upon landmarks. Whee!
I'm working with another new editor to clean up some of this, and the user (the father, presumably) has said he'll clean up what he can find as well.
If it's true, it's definitely the first time I've been told "my child did this", but it doesn't make me mad because when I was but a wee laddie, I was drawing maps all the time too. Had this technology been around back in those halcyon days of yore, I'm sure I would have completely ruined most of central Alabama for everyone.