The IT guys probably got orders to crack down on bandwidth abuse as well, since the company isn't paying you to sit there and read fanfiction all day. That there's "mature" material is just icing on the cake. That's generally why ff.net was blocked when I was still USAF.
I'm trying to find a fic where Naruto is killed and the seal destroyed at the Valley, but the fox manages to partly resurrect him before it gets taken. The result is an undead Naruto not-really-angsting (he's undead, so he doesn't have the hormones for emoting). I remember when he first resurrects, Kakashi is freaked out by the hole in Naruto's stomach filling with blood which then solidifies into new flesh. I lost track of the fic a few years ago, and it was around chap 5, with Naruto and Jiraiya accompanying the Sand trio back to their village. Naruto also has periodic cold spells where his body just stops working. I think it was called Forever in a Day, but I'm not sure of that and I haven't been able to find it on FFN.