I read that as suggesting that far-right extremists are essentially trying to normalise and mainstream their extremism by placing it in a context of contemporary culture, memes, issues, language etc which - apart from its deranged hatred content - could otherwise be the inane chat of mumsnet, .net or kickback. 'I'm a totally average normal bloke who just happens to hate blacks/jews/muslims/pakis/gays. I don't really want to hate them but any reasonable ordinary bloke like me can see that they're responsible for X, Y and Z. Ordinary blokes like me should really be taking direct action. Anyone fancy a pint?'.
This episode has really challenged me on my fundamental belief that free speech trumps everything. I have always thought that you cleanse hatred and lies with facts and truth. I'm not so sure now.
As far as comments elsewhere on this thread go I'd just point out that the proportion of Muslims, Jews, Christians - and pretty much any other religion - who go out and commit terrorist acts are tiny. This isn't a religious problem, its an economic, societal and cultural problem.