Haven't checked all titles but i am pretty sure most of them are original ones.
I mean Sasha Grey was one of the most popular pornstars for about six years (2006-2011) and one of the few porngirls you really can still call porn
STAR nowdays. She was and is very well known & popuar in AND OUTSIED of porn - which is pretty rare.
So porn producers of course loved to do scenes with her adn because of that she did really, really a lot of scenes and took uncounted amounts of dicks