Anti-govt extremists a growing threat

A NSW Police report has identified anti-government extremists referred to as "sovereign citizens" as a growing cohort and a potential terror threat.

As many as 300 so-called sovereign citizens have been identified in NSW with police records showing the number having nearly tripled between 2009 and 2012.

The NSW Counter Terrorism and Special Tactics command assessment suggests some of those identified have "the motivation and capability to act against government interests and should be considered a potential terrorist threat", according to the ABC.

Interactions with police had increased 50 per cent in 2011, with a "notable increase in threats of violence", the ABC reported.

In the US, sovereign citizens are regarded as the chief domestic terrorism threat, while the Federal Bureau of Investigation official describes the cohort as domestic terrorists.

The report comes amid ongoing debate over the threat from Islamic extremists and terrorist groups such as Islamic State.

Professor John Esposito, the founding director of the Prince Alwaleed Bin Talal Center for Muslim-Christian Understanding at Georgetown University in the US, said anti-government people and the likes of white supremacists represented a greater risk than Islamic extremists.

"Most Americans don't even realise that the latest FBI reports basically indicate that our number one danger are white anti-government folks," he told AAP on Monday.

Speaking on the sidelines of a conference in Sydney on Islam, Prof Esposito said the West was not responding in a rational way "in terms of the actual magnitude of threat that exists" from Muslim terrorists.

"It's a fraction of a fraction of a fraction of a population of Muslims," he said.

The ABC reported police intelligence of incidents involving sovereign citizens in Australia ranged from displaying homemade registration plates and "plans to use paint bombs to disrupt court proceedings", to making plans to kidnap a judge, judicial officials and a police officer.

In 2012, a person or persons considered sovereign citizens threatened to burn down the home of a judge and "cause harm with firearms", and had "plans to murder Sheriff Officers if they attempt to seize property".