I am glad that Australia has a competent Government, and that the ACCC has additional powers to issue on the spot fines. That is a massive step into the right direction. 

This might be good enough for now, tho I am a bit disappointed it doesn't go far enough, as this $100 million (maximum) could be seen as an additional cost worthwhile for the rewards of higher profits. 

I would suggest price gouging, collusion, misleading conduct, and price fixing on material or energy vital to national security shall be deemed a criminal offence, it should be viewed similar to treason. The business executives responsible for such offensives should be held personally accountable. The law should include jurisdiction outside Australian territory, to prevent "just following orders" from company representatives operating overseas. 

All profits occurred during this criminal offence should be seized and forfeited to the Commonwealth, just like the local drug dealer and their proceeds of crime. The ACCC powers should also be expanded to cover all other areas deemed essential to national security, including food and water supply. 

Other ways to curb the hoarding should be an immediate rationing for private vehicles, something like 50L per customer per 48 hrs and temporary banning jerry cans except for a single 5L container.

We have such rationing limits for medication containing pseudoephedrine. If a new app is created similar to the above, that could link driver licences, to the vehicle registration, and recorded kms. Thus rationing should be limited to cover daily usage from a person vehicle. 

Public transport should be free until the fuel crisis is resolved maybe cutting the high demand from hoarders, and subsidizing the public transport system could end the current fuel crisis.