Hacker News Reader

So far it hasn't been at all, that was the point of the test:

"The system had been operating in a trial mode, without publicity for three months, during which it received several genuine reports and no hoaxes, according to Samaritans."

Doesn't sound too bad.

It will be abused anyways, this is the Internet. Facebook could simply log IP (as if they don't already) and report the trolls.

It should be fairly difficult to abuse, since you need to link to the suicidal post in the contact form. I assume a human at Facebook will look at it before sending in the SWAT team.