Most of the time it's copyrighted pornography that's used as the base. Interestingly I've heard almost nothing about that part of the equation: the IP infringement angle. I doubt most of the content on Mr. Deepfakes would fall under the DMCA free use exceptions.
How do they define "deepfake"? How realistic does it have to be? Does there have to be pornographic intent? Does it need to involve a computer? A GPU?
If these questions are not precisely addressed, it could criminalize a whole range of stuff including manually illustrated satire. I'm sure the ruling class won't lose sleep over that, but perhaps we should...