Joe Scarborough's defense of Brian Williams amounts to a warning to people in the media and politics: I know a lot about many of you, too. On today's Morning Joe, Scarborough ominously said: "in over a decade in this news business, it is fair to say looking straight in the camera, I've seen a lot, I know a lot, and I know that there are very few people in this industry or in politics that could live by the standard of perfection. Cast the first stone? I would be careful." View the video here.