Martyr's

Has anyone else seen this horrible, extremely disturbing movie from France —

Yeah, like you, ive watched the Hostel Movies (which i enjoyed) we probably have the same taste coz i like those kind of movies, but for some reason "Martyrs" totally freaked me out. I saw it a year ago and even now it sticks in my mind, no other movie had such an impact on me as this one.
I think it was the Relentless Degradation and Torture of that poor girl, and to be "Skinned Alive" with what seemed like no anastheisia just made me want to vomit.
I can believe that there are "Cults" around like that, and i hope to god this doesnt happen in real life.
From my memory, wasnt it a true story ??