How much can you narrow down my identity from a comment, I really have no idea? That'd probably only cause trouble for me, by the way.

I don't know; it depends on the details. I know from my time as an admin on Wikipedia that we were often able to contact local authorities or family, often using IP addresses. (I imagine suicide is quite troubling too.)

There's really no reason someone couldn't do those things even if they did have contributions under another account.

It reduces the odds.

And I'm curious, what do you mean by "attack" other than trolling?

I think that if you can't think of ways in which suicides, real or faked, could be used to attack a group, then it's probably better if I don't list every idea that comes to mind.

There is a difference between a suicide note by someone determined to kill himself and a plea for advice from someone who doesn't particularly want to die but might kill himself all the same.

I am not an expert on suicide (which is one reason I think a LW suicide policy is a really good idea), but I understand many or most suicide attempts fail so I'm not sure there is a difference or if the difference is important.