From my understanding and not sure against Feds but, you have to advise whether or not you are recording video/sound (or not). The police officer will then request for you to either turn it off (Which you have to) or he will acknowldge and proceed with defecting you
Anyone have any cop m8's? My m8 has a cop friend. Might get him to ask him. Also, becareful, you can be arrested for not having more then $5 on you at all times (True law - but not policed ) Infact, a guy in Melbourne got recently questioned for not having any money on him - mind you he lost his wallet.
Funny laws.