Board Thread:General Discussion/@comment-173.24.245.109-20140830233727/@comment-6604690-20140902091955

So overall, it wasn't possible to crash SAO's sever because of Kayaba himself.

Regarding the EMP question, I think it'll help to fry the Nerve Gear; in short the person wearing the NerveGear will be electrified and die instantly, regardless of what the player was doing that time. Guess it would have the same fatal effect when the NerveGear is forcefully removed(or if someone killed the player in real life).