UPDATE: Looks like the above photo is a photoshop. Thanks to JM for finding the original. These obrez pistols do exist and the bottom photo does appear authentic.
Wow! Just when you think you have seen it all, you see a photo of a Mosin Nagant pistol!
Go read about it at Real Gun Guys.
UPDATE: AB posted a link in the comments to this photo of one that appears have been cut down to only a few inches of barrel!