I’m in more sympathy with Yonatan Gershon’s answer and its free speech absolutism than with Ted Wrigley’s answer which relies on intent. Intent is a very hard thing to diagnose, and I’m not sure I trust a judiciary allied to power to judge it fairly; and of course, any dissidence can be regarded as disruptive and to be quashed.
But I’m going to expand on Jacob Holcomb’s answer, which I think makes a more useful distinction (though I draw the dividing line elsewhere):
We can talk about the effects of depression, but I’d prefer not to delve into discussing suicide.
Ruling a whole topic out of bounds is lunacy, and it’s inviting protest and circumvention. It was lunacy when Melbourne University banned books about jihad from being borrowed, to much media hoopla, just as it is lunacy to ban ownership of Al-Qaeda literature: if you can’t study your enemy, how on earth do you intend to combat them?
If speech is to be policed for noxious intent, as hate speech or advocacy of criminal behaviour, you have to draw a very careful boundary. Unlike Jacob, I don’t think discussing suicide should be banned; as long as there are some proactive disclaimers and steps around mitigating the effects of that discussion. Whenever anyone’s suicide is mentioned in the press here in Australia, the phone number of the suicide hotline is given as a footer or as a fadeout announcement. That, it seems to me, is reasonable. And though I would want a high bar on it, outright advocacy of suicide, or of terrorism, should be curtailed in the mass media. The high bar means that discussion of Islamic grievances, or of the nature of jihadi thought, should not be blocked—although, again, there should be mitigation and disclaimers accompanying the discussion.
I also think banning Mein Kampf is counterproductive, btw, or The Protocols of Zion. And good luck blocking their dissemination through the Internet anyway.