I know Fluxmeister just puts his NHMK logo at the start of his videos without any contact info, but there's editors like jbone, Tsunami Jones, etc who don't put anything at all. Do you know how many editors claimed that they created Maboroshi's "Hero of the day" Dragonball video? Or Duane Johnson's "Particle Man" because they had no credits? Maybe the technology wasn't available at the time of their creation (hell, Particle Man was made in 1996 with 2-vcrs). In this age of booschack theft and kids thinking they can remove your credits and claim fame to your videos, nobody's safe.
Maybe it's understandable if you don't want a million people trying to contact you from a video, or if you don't use that site/email anymore, but if you made something, wouldn't you want to attach your name to it? I think there's people on booshack already claiming that they made TJ's TF2 video now.

Since the above members don't really post here anymore, what are your speculations on why they never put credits in their videos?