In Australia it was rated R for:high level child sexual abuse themes, high level sexual violence and pedophile theme. Which pretty much sums it up exept for other sexual acts of a more consenting nature. However in america the NC-17 is most likely down to a prolonged sequence at the end of the film involving sexually explicit duologue. Child molestation, other sex related activitys and rape are all discussed in depth, and implied visually in a much more suttle manner, never the less it was enough to earn that rating.

Very frank depictions of child molestation, a rather disturbing scene of a confused boy (molestation victim) performing a sex act on another young boy, a rather violent male rape scene, etc. The whole film revolves around material that most people would find uncomfortable, to say the least.
Fighting the frizzies, at 11.