What are police allowed to do at protests and who keeps them in check

Where a person does not follow a police officer's lawful direction, they are contravening the law and can be arrested.

However, move-on powers are limited when there is a peaceful protest. Police cannot direct a person to move on just because they are peacefully protesting something, picketing or publicly sharing their views (such as speaking loudly or carrying a sign).

States and territories have also criminalised certain behaviour related to protests. For example, it is unlawful to harass, intimidate or threaten a person accessing a place of worship in New South Wales.

Police can use force to maintain peace or prevent violence. The force used must only be "reasonably necessary". This means police can only use the minimum amount of force needed that is proportionate to the event.

It might be appropriate for police to restrain a protester using their hands or handcuffs and individual circumstances will be relevant to whether use of force is permitted. Lethal force, though, would not be permitted against a protester unless a protester was endangering the life of another person.

Injuries can occur during police arrests. It has been alleged that Hannah Thomas' injury arising during her arrest was the result of "excessive use of force". However, just because a person is injured during an arrest does not automatically mean a police officer acted inappropriately.

Who holds police accountable if someone gets hurt?

Where concerns arise about police behaviour during a protest (including the use of force or other actions), there are different ways police can be held accountable.

Policing organisations have internal processes for investigating police conduct. Each policing organisation has a professional or ethical standards unit that investigates allegations of conduct.

But integrity bodies have flagged police investigating police can perpetuate potentially problematic "cover up behaviours that can mask police misconduct".

Australia's states and territories also have independent statutory organisations which target crime and corruption in the public service. These are generally corruption or integrity commissions and apply to all public service workers, including police officers. The relevant ombudsman can also assist to resolve complaints.

Community members can also sue a policing organisation for injuries they sustained during an arrest.