I have now re-read the original article, in which David K. refers to four threats - for Australia and others. Those threats are:
domestic radicalisation, foreign fighters, the effect of Islamic State on regional and global jihadist groups, and the destabilising effect of conflict in the Middle East.
Guy Fawkes was a Catholic radical who in 1605 attempted to blow up the British parliament in London, effectively to decapitate the establishment and is marked each 5th November with bonfires, fireworks and in places more. This article links him to the contemporary scene:http://www.telegraph.co.uk/history/1...r-change.html?

Here are key passages reagrding domestic radicalisation:
..the mobilising effect of overseas terrorist groups on people in our own societies — is the most immediate threat.....The randomness, unpredictability and copycat nature of these attacks, which require little preparation, give few warning signs, and are difficult to prevent, is what makes them so terrifying. Attackers are often disenfranchised, alienated, marginalised young people, frequently converts: society’s losers, who see radical Salafi-jihadist ideology as a way to be part of something big, historic and successful. They’re not really self-radicalised. Rather, they often access online terrorist materials (increasingly in English) for inspiration, instruction and training, or link up online with radicals who groom them for action.Defeating this threat is partly a matter of community policing to identify and engage at-risk individuals, and partly a matter of detecting and monitoring access to online forums, radicalisation networks, social media and online training materials.
Despite the fear these attacks create, police and intelligence agencies have a pretty good handle on this type of threat, but in the long term this brings a potential cost to civil liberties and community cohesion.
I have doubts that in reality anyone officially has a 'handle' on this problem, that includes the police and intelligence agencies. Too many of those id'd as 'at risk' here suffer from mental illnesses, not radicalism. 'Detecting and monitoring' sounds neat, it is not and for this threat threatens more of what we seek to defend.