Yahoo's still popular photo host Flickr has a problem with Google's short URL service. Trying to include a short URL to a charity collections page today produced an error which stated since spammers had used it too often it could not be used again. I had to take the goog.gl link out and replace it with the original.
This was no skin off my nose. I was using the short URL simply because it was the one skyped to me and it's useful for tracking. I replaced it with the full URL and all was well. I can imagine some media owners might be less happy if they find their domains blocked by Yahoo in this way.