Australian competition regulator the ACCC is gearing up for a court battle with five "continuing investigations" likely to end up with prosecutions.

Chairman Rod Sims has been widely quoted this week on issues on which he says the tech giants chose not to act, and says the duo must "either comply or do not do business in Australia".

He is not fazed by earlier threats that they might withdraw services from a country in response to local laws: "I do not think this will happen here," he said.

He is critical of a business model which creates large platforms for profit, but "does not take responsibility for what happens" on those platforms.

Investigations include whether Facebook breached consumer law by allowing users' data to be shared with third parties and whether Google has collated users' location data illegally. If these proceed to court and behavior by Facebook or Google is found to be wrong or illegal, that would become "behaviour they can't do again".

In its recent report, the ACCC presented 23 recommendations covering consumer data, digital dominance and the protection of public interest journalism. While the Australian regulator was "very closely aligned" similar organisations in other countries, it would act alone to introduce "legally enforceable penalties" through investigations such as those ongoing.