For the 206th man on manus island

96E Minister may determine that certain visa holders must complete revalidation check in the public interest

(1) If the Minister thinks it is in the public interest to do so, the Minister may, by legislative instrument, determine that a specified class of persons holding a visa of a prescribed kind (however described) must complete a revalidation check for the visa.
— http://rran.org/

Thus the minister can discriminate against people by class, ethnic origin, nationality, religion, date of arrival, age, gender, etc. No evidence of wrong-doing would be required. Asylum seekers and refugees who are already in Australia are the most vulnerable, but these extreme powers could be applied to any non-citizen. Coupled with DIBP's blocking of many migrants from taking their final step to becoming citizens (despite them having been awarded citizen status) Australia is becoming more and more authoritarian, where extreme power is wielded unchecked and rules are changed arbitrarily.