I just remembered his Tumblr on a whim. http://shutupandkeepwalking.tumblr.com/
Hasn't updated in 2 years. Guess he's done with the SFM porn game, which is a shame since his GIFs were especially high quality.
The reason why I couldn't find Johnny Ku is his name was spelled Jonnyku, and his Tumblr seems decativated–but unlike Notyourregularidiot AKA Shutupandkeepwalking, Jonnyku's GIFs are still readily available on Paheal.
Well, there's a mystery that's no one needed solved. Let's carry on then,