I think that it is a form of picking, in the same vein that a pick gun is picking. It's a quick way to open a lock without a (proper) key. However the lack of real skill in the technique makes this a less than stellar method.
As for concerns of the criminal element using this, it's only the dumb ones who don't know this trick. Any crook worth his craft will research first and use free resources out there to try and not get caught.
The info has been out there for a while. The 2001 edition of The Complete Book of Locks and Locksmithing by Bill Phillips has a description of bumping. I'm pretty sure that earlier editions also mention it. I got my original read of this book through the public library, it's not exactly restricted knowledge.