I thought the Australian Communications and Media Authority regulations did not permit the unauthorised interception of radio calls, but I've not been able to find it in any legislation. If it were so, AVDATA's data harvesting could be stopped dead.
The matter of expecting the aviation community to bear the onus of sorting out incorrect charges would be eliminated if users notified AVDATA that a minimum $50 back-charge would be levied for administrative time, and would be deducted from any current or future charges.
Airports are an asset to the community they serve providing access for business and tourism, medical evacuation, urgent freight etc. Imagine if the local council photographed number plates and sent a bill every time a car or truck rolled through town for "so called access".