It was actually blown recently (Aug. 15th) thanks to a lawsuit:

Another infringement suit has been waged by the MetArt Network against a well-known online adult brand. (...) This time around the target is adult tube site XVideos.com and two related web properties (...) along with defendant owners Stephane and Malorie Pacaud of France

http://www.xbiz.com/news/197942

Of course, those names could just be covers.