Av,
If you hold an RAA ticket you can only fly an RAA aircraft. If you hold a PPL you cannot fly a RAA aircraft unless you hold a RAA License.
As stated "IF" it is unregistered and "IF" the pilot is unlicensed then it is NOT a issue to be delt with by RAA and CASA is responsible for action.
Sadly you cannot stop people from buying things that they are not qualified for use. Hence a 10 Year Old can buy a car!
As stated by others the problem here is Joe Public keep seeing small aircraft crashing thinking what a dangerous activity it is!!!! This means more pressure to shut airfields and regulate our activities.
For my two cents worth if you see something not right = report it. You don't have to give your name!!!!
Jim