Advice Giver

A student has begged me to read his writing and give him honest feedback on what I think. I knew before reading it that it was graphic, horrorific, and that his parents knew he was writing this as fiction. I also want to preface this with saying that I have watch every SAW movie out, so I am not sensitive to gore. However, I was overwhelmed because there was mutilation of babies.... Maybe that is where I draw the line. I gave feedback on the paper and even crossed a section out that even I felt could be literary taboo. I am afraid I might crush this new writer. I never wanted people to read my work because I hated the criticism. I did like some of his sentences. They were eloquent and they were meaningful and his story was wonderful because I could feel the pain that was haunting this student. But how much is too much in literature and where our world has gone today? Are there any subjects that are off limits? Or, have we gotten to the point that every new story has to overtake the last and be more shocking? How much is too much? That is my question and I would love to hear what all you others have to think, especially with the idea of free speech being front and center.