Police in Hamilton, Ontario had a conundrum on their hands- how to catch a killer when there are no witnesses, only a grainy security video that shows a person of interest, and not even his face?
Post it on YouTube (the video appears to have been removed from YouTube, but I found at another site, which I have to say, is nowhere NEAR as good).
George Gallo, a 24-year-old man, turned himself into police about two weeks after a 72-second surveillance video from the concert site was posted online.
Police say the clip didn't lead to any witnesses coming forward, but the extra attention paid to the case because of the use of YouTube likely encouraged the suspect to turn himself in.
This is what life is like now- the mere existence of a video that doesn't show anything, and that didn't actually produce any witnesses prompted someone to turn himself in. It is a lesson that Michael Richards learned the hard way- you are always on camera, and the entire world is watching.
There are other examples of investigators using YouTube to find witnesses, and this is probably no different from police releasing video to TV news in the search for leads, but if it worked once, you can be certain it will become more common.