Everyone in Australia can protest, but the finer details differ ...

From the lawns of Sydney's Hyde Park to the steps of Melbourne's state parliament, thousands of Australians gather each weekend in public places to protest.

It's a trend that appears to be rising across the world, with data from some researchers showing the global number of protests each year tripling from 2006 to 2020.

However in recent years, protesting has become increasingly subject to legislation and regulation, with protesters running the risk of being arrested and jailed over high-profile demonstrations. 

Here is what you need to know about protesting in Australia.

Do I have a right to protest?

While many Australians might assume they are legally protected to protest in support of political causes important to them, there is no simple or overarching 'right' to protest in domestic law.

"The short answer is we don't have a right to protest in our constitution. There isn't a law we can point to at the federal or state level that says everyone has a right to protest," University of South Australia associate professor Sarah Moulds said.

The right to protest comes from the implied freedom of political communication found in the Australian Constitution.

It means while Australians may not explicitly have a right to protest, governments are expressly forbidden from introducing any laws which might impede a person's right to express themselves or protest.

Australians' ability to protest is implied but not explicitly set out in the constitution.(AAP: Joel Carrett)

Experts say the level of legal risk for people in Australia who attend rallies, demonstrations or engage in other acts of protest depends on where they are, what they are doing and sometimes — the discretion of police.

But the right to protest and assemble is protected under international law and is considered part of participating in democracy in Australia, which is legally protected.

"We really do value this concept in our society," Dr Moulds said.

Do I need a permit to protest?

While every Australian may have the implied right to protest, the level of permission needed may vary from state to state. 

The City of Melbourne and the National Capital Authority in Canberra do not require any permits or registration for public protests, whereas the city councils of Adelaide, Perth, Sydney, Hobart, Darwin and Brisbane do.

While it is not a direct offence to hold your protest on public land, a permit provides protection from certain criminal charges like obstructing traffic or other pedestrians.

All councils either strongly recommend or require local police to be notified if a large protest is taking place.

Rallies in public places will sometimes require permits, depending on the local council.( ABC News: Simon Winter )

Hamish McLachlan is a human rights lawyer and interim chief executive with Fitzroy Legal Service, and said local protest laws fall in a legal grey area.

"There's a question there whether those kind of local laws are really lawful, because like the move on powers, there is a specific carve out for protest activity," he said.

"Clauses like that, that require that kind of compliance, really can have a chilling effect on people's ability to protest."

Is protesting ever against the law?

While there is an implied right to protest in Australia, several states have recently introduced laws which target specific kinds of protests.

In South Australia last year, following a protest by Extinction Rebellion that caused traffic chaos, lawmakers quickly drafted and passed laws which increased the penalties for "obstructing a public place". 

In Victoria last year, the state Labor government passed laws which tighten restrictions against protesters in active forestry zones and increase penalties for those who breach them.

Laws have been legislated targeting certain protest actions in recent years.(AAP: James Ross)

Associate Professor Moulds said the new laws typically target where a protest is happening, like on a major road (New South Wales), or forestry site (Tasmania/NSW/Victoria), or a particular behaviour, like when activists attach themselves to things using a clamp (Queensland).

"What's problematic about those laws is that unless they're very, very targeted, they're going to pick up a whole lot of people … who feel like they're exercising their democratic right," she said.

Dr Moulds said some of these anti-protest laws, like in the case of South Australia's, are drafted quickly and are broad in scope. This can be problematic.

"We can create a law that has either unintended consequences, because it captures things we don't want to be captured, or is heavily reliant on police or enforcement discretion of when it's going to be used and how and when people will be arrested."

Some experts have expressed concern over how protest laws are enforced.(AAP: David Crosling)

What are the police able to do?

While police in Australia have the authority to use 'move on powers' if they believe people are obstructing a place or causing a nuisance, there is an exception for genuine protests.

That doesn't mean protesters are completely immune to charges though. 

"We often see police will charge people with allegations of graffiti or property damage for putting up bills or stickers, or failing to provide name or address," Mr McLachlan said.

"If it escalates and then becomes a sit-in, there's other things that police might be able to charge people with, such as obstruction of a public carriageway, or failure to comply with directions from police and directions under the road safety rules."

While police cannot ask protesters to move on, they may charge them with other offences such as graffiti or obstructing a carriageway.(ABC News: Nicole Asher)

Police are also allowed to ask a person with a face covering or mask to identify themselves, or — in Victoria — leave the area altogether.

A Victorian police officer must reasonably believe that the person is wearing the face covering primarily to conceal their identity or to protect themselves from the effects of crowd-controlling substances like capsicum spray.

Police also have the ability to search a person if they reasonably suspect they are carrying something stolen, dangerous or otherwise illegal. 

How effective is protesting?

While protests fill the streets of major cities both in Australia and around the world, experts say it is near impossible to measure how effective they are in achieving their goals.

Researchers from Harvard University have found some evidence that non-violent protests are around twice as effective as violent ones in bringing about change, but conclude there is "no blueprint for success".

Sean Scalmer is a professor of Australian history at the University of Melbourne, and said there was no simple way to measure the efficacy of a protest.

"The first point would be that different protesters have different aims," Professor Scalmer said.

"Sometimes they outline what their aims are explicitly, sometimes they do not, and sometimes the impact of a protest is not immediately evident."

He said the fact that protests usually work in concert with media scrutiny, political action and more formal lobbying make it hard to tease out the direct effect of any single protest movement.

One of the first International Women's Day rallies in Australia, held in Melbourne in 1975.(National Archives of Australia)

But Professor Scalmer said protests could be viewed through a different lens, where the action itself was as important as direct impact or change.

"One thing to think about is, to what extent is the expression of public solidarity an end in itself," he said.

"Whether or not the Australian government changes its policy, the participants in the protest may draw meaning and may draw a sense that something has been achieved, irrespective of that broader shift."