Please note, I derived the following suggestions to the best of my knowledge of Common Law, which still applies in Australia according to its Constitution. Police officers most likely have a different attitude of what they are entitled to, and might use force and/or intimidation to get what they want.
Stay calm, friendly and firm.
As soon as you loose your temper, you might forget any of the following suggestions, and do something stupid. Yet as long as you haven’t committed any crime, you have the rights that apply under Common Law for dealing with any requests from the police.
Identify yourself or not?
At common law, a citizen is under no legal duty to identify himself or herself to the police. The exception to this principle is where the police see the person in question committing an offence. Victoria has introduced Statutory Laws that entitle police to identify you, but Statutory Laws require your consent to become binding. Demanding to be treated under common law cannot be treated as obstruction, however, police might coerce/intimidate you to contract with them.
Depending on how critical the situation is, you might want to film the conversation before answering any questions. Documenting your interactions with the police on video can provide valuable evidence in case of trouble.
Am I under arrest?
As long as you haven’t been caught committing a crime, you don’t need to cooperate with police. Talking to police can get quite repetitive, as they usually expect compliance. Remember, as long as you haven’t contracted with them, they are an authority for you, not over you.
What is the charge?
If police wants to arrest you, they have to name a charge against you. Not giving your ID isn’t a criminal offense, and isn’t obstruction either. Stay calm and ask them: “Under which law are you acting?” Remind them friendly that they don’t have authority over you unless you committed a crime.
Do you understand?
Never answer this question from a police officer with yes, unless you want to get into trouble. This term sounds like plain English, but it’s a special legalese term. By answering yes, you enter into a contract with the police officer, and agree not to be treated under common law, but statutory law. ‘Do you understand?’ translates into ‘Do you agree to stand under my authority?’ An adequate answer could sound like this: No, I do not stand under your authority. Being (or acting) stupid cannot be construed as a crime, if the police officer looses his/her calm on camera, the odds in a court case can be in your favour.
Under which authority are you acting?
Ask this question if police insists to request something you don’t want to do. Victoria Police display the Crown on their badges, which means they have sworn an allegiance to the Queen. The Queen warrants that anyone is entitled to be treated under common law, which most police officers have not the faintest clue about. However, as long as you know your rights, stay calm, friendly and firm, police officers can held liable for infringing your (god-given) rights. Depending on how confident you feel, you might remind the police about their unlawful activity, best when it’s documented on camera.
Public space is public.
Although some statutory laws have been made for move-on orders and random searches, these have to be announced a week in advance. Unless you’re breaching the peace, police have no right to ask you to leave a public spot. If you breached the peace, police have to explain first how you did it.
More about space
While freedom of movement seems obvious for public space, different rules apply for private property. Although being technically private property, places of business are basically similar to public spaces. Interfering with political protest in places of business is therefor similar to interfering with it in public space.
Crimes Act 1914 – Section 14 / Interfering with political liberty
Any person who, by violence and threat of intimidation of any kind, hinders or interferes with the free exercise or performance, by any other person, of any political right or duty, shall be guilty of an offense.
Penalty: Imprisonment for 3 years.
Translated into common language this means police breaking up a protest are usually committing a crime, punishable by 3 years of prison.
Know your rights.
If you’re planning to do direct action, investigate as best as you can the legal situation you’re entering into. Stay calm, friendly and firm when explaining to police your understanding of the law. Police doesn’t the law most of the time, but usually can be stopped in their tracks if reminded that they are breaking laws by what they do or want to do.
Common Law is simple.
As long as you avoid contracting with police, your intuitive idea about right and wrong most likely reflects common law. However, as police is trained to follow orders, it might save you from harm to comply when threatened with violence. If you have given your ID without committing a crime, or answered to “Do you understand?” with yes, you already contracted with police, and therefor entered the area of corporate law, which acts against the interest of citizens.
Comments, corrections and additions are welcome. I wrote all of this to the best of my knowledge, based on my research and understanding of the legal system. Knowing your rights might not save you from arrest or other problems with police, but will provide a sound basis for potential court proceeding. Use with care and sound judgement.