That's why I agree with Zebo, HAL and Shawn; doing this on a suicide hotline is way, way different from facilitating the suicides of the terminally ill. Such a person should be charged with anything and everything possible, even things you know won't stick. Make his life as much of a living hell as the lives of the families of those on whom he preyed. Such a person in my opinion is worthy of execution; although there is probably no such law bearing that penalty, morally he is on the level of child rapists and murderers.
If he talked them into killing themselves on a suicide HOT LINE on the PHONE where he is supposed to be talking people out of suicide then yes, I agree it should be a crime. Despondent people go to a suicide hot line because they are not sure if they really want to kill themselves or not.
But from what I read, it was a suicide CHAT ROOM ONLINE that he trolled in, where depressed suicidal people hang out and talk about killing themselves, and they are not seeking advice to talk them out of it which is an entirely different motivation.
They are seeking moral support for what they want to do, and are trying to get up the courage to do it and decide how. Understand that if someone was actively trying to talk people out of it there they would be unwelcome and they would be looked at like a troll and blocked or ignored and not listened to. So that then becomes a crime just for hanging out there and telling people what they wanted to hear when they went there?
The fact he was pretending to be a female nurse is pretty creepy, but when typing online it's pretty easy to do, and might have given him more of a compassionate persona for all I know. Since none of us were there reading the text, all we can do is read the sensationalist media hype being reported that might or might not be true and speculate about the motivations.