Why has the drift to an anti-dissent police state in Australia accelerated since 2014? It's a conjunction, or perhaps coincidence, of several factors.
The Liberals' illiberalism
The purported liberalism of the Liberal Party is only ever heard of in opposition. When Labor's then-Attorney-General Nicola Roxon raised a data retention scheme, the opposition Liberal partyroom expressed concern and George Brandis and Malcolm Turnbull condemned it. After a change of government, Brandis and Turnbull led the charge to implement what they had condemned in opposition. Being in government literally erases the liberalism of Liberal moderates, who transform into national security hardliners the moment they obtain power.