Re: How "open" is OpenStreetMap?
What possessed you to make such an accusation? What's in it for you?
No accusation, nothing in it for me. Just a back-of-the-envelope calculation,. Even if all the amateur mapmakers in the US were off on their bikes like Dave Pickles (above) I don't think there are enough of them, with the aerial surveying equipment they need, to turn out the huge level of accurate detail that we see in OSM.
I'm not suggesting any sort of criminal conspiracy, but I suspect many people have picked up a "free" map at the tourist office and thought "Oh, I know, I'll load it into OSM for everyone else", etc.. Nice idea, but it ignores that little "(C)" at the bottom.