Voice just asks for name, email, and two different selfie photos.
Well how do they prevent someone from just signing up with a bunch of different different names, emails, and selfie photos? How do they determine if the photos are of someone who has already joined? Are there people who approve new users?
I'm guessing this info is already available somewhere so if you have a link to something like that I'd be interested to read up on it.
My understanding is it uses some kind of 3D face recognition technology using multiple selfies (one zoomed in after the other) so you can't upload a photo, but have to take both photos in real time.