We'd be gullible if we thought that the digital space was any different from the FtF space. The full diversity of sense-making and behaviour from people of various persuasions will clearly be able to find a voice and constituency in the fluid and far reach medium of digital conversations.
This recent BBC article http://news.bbc.co.uk/1/hi/technology/8097979.stm is certainly thought provoking.
This merely serves to underscore the need to develop the education and critical skills of all digital media users. This will enable them to readily challenge the flawed logic of the hate-mongers and spot a gross generalisation and simplification at a 1000 meters.
People on the whole have become more media savvy. They know that people have agendas when they communicate. The disturbing feature of social media is that it enables 'the disturbed' who might have been previously disjointed to connect. And in this 'connection' to believe that they are establishing a general norm instead of a perverse small group norm.
Do we see a Hate 2.0 career path here? Does leaving a flame comment mean you will become a Troll, does becoming a troll mean you are predisposed to finding affinities with more established hate groups, does an on-line hate group manifest itself in physical action?
There might be a saving grace in the very nature of social media itself! The power of crowds only really works in the physical realm. Crowd psychology is a powerful thing. http://en.wikipedia.org/wiki/Crowd_psychology The Nazis may have utilised the new technologies of film and radio but it was only in the setting of mass public meetings that the virulence of their thinking took hold.