Over the past six months members have filmed themselves entering or attempting to enter court houses, police stations, local council chambers and commercial offices across the country.

During these interactions, an NDA “sheriff” typically approaches a polite, but often confused, front desk worker to proclaim Australia is now a “demilitarised zone” and that all government authority has been dissolved before handing them a written notice.

The notice warns “failure to be fully compliant” with NDA’s rules “will certainly place you at severe risk of possible persecution, imprisonment or financial ruin”.

Over time, these interactions have become more confrontational.

Video seen by ABC Investigations showed police forcefully ejecting members of the group from Gympie Court House in May.

What in tarnation?