these are unfixable people

You can't undo the awful things they did, but I try to avoid language constructs like 'these are unfixable people' in favor of 'we don't know how to deal with this.'

One one level I find Ander Brievik appalling because he was willing to murder a bunch of innocent people to uphold the nazi ideology which finally gave him a sense of identity and direction. While he must have had a gaping void at his center in order to go to such lengths, it's not so surprising that a badly alienated person clings to a radical ideology that offers them the social and emotional validation they crave, even at a far remove.

On the other hand I'm similarly disturbed at the people who originate and promote ideologies of this kind and who target their arguments precisely at such psychologically vulnerable types, in the knowledge and expectation that their ideas will be acted on by others. Brievik's manifesto, for example, heavily plagiarizes a monograph on political correctness by William Lind, co-founder (with the late Paul Weyrich) of the ultra-libertarian Free Congress Foundation. Lind is an influential military theorist who has done a lot to shape the debate on modern counterinsurgency; also a self-described 'neo-Victorian' and not-so-secret proponent of genocidal policies. But he hasn't shot anyone in person, so that apparently makes it OK.

I'm very much anti-censorship and in favor of maximizing personal freedom of expression, but this inevitably leads quandaries like how one should respond to an ideology that argues for the elimination of other peoples' political rights or even existence. Traditionally for liberals 'the solution to bad speech is more speech,' but this notion is predicated on the assumption that rational discourse is the norm and that fair competition obtains in a 'marketplace of ideas.' Increasingly I don't think that either is true that we have run into the limits of the market as social arbitration mechanism because it's apparent that you can attract people to authoritarian politics almost as easily as you can attract people to any other kind of brand.

I'm not sure how you systematize this; I don't really agree with Germany's approach of heavily censoring any expression of nazism in public discourse but I can see why they adopted it. For me the rule of thumb is that I won't give the time of day to any ideology that purports to sort people by their personal characteristics rather than by their behavioral ones or employs fallacies to achieve the same ends (eg 'members of (group) did these bad things, people with (characteristics) are members of (group), therefore said people are bad). Now on the individual level you can employ forensic debate to pick apart someone's specious argument and force them to a position where they either affirm or abandon that ideological identity. But on a collective level that's not really practical and what frequently ensues is a race for the lowest common denominator of political discourse, to the point that point that crackpot outfits are now treated like credible sources in debates on the news.

The internet has disrupted the media business in no uncertain terms, but it's highly questionable whether the public is actually better informed as a result. There's a lot more data available, and for news junkies like myself that's like an endless supply of free heroin, but our political discourse looks less and less like a creative exchange of ideas and more and more like an elaborate trading card game.