HONG KONG (BLOOMBERG) - Last summer Hong Kong's protesters called for a revolution as they occupied the city's international airport, marched in the millions and mocked Chinese President Xi Jinping as a Game of Thrones villain.

This year's different.

A sweeping national security law imposed by China in June and Covid-19 restrictions have rendered the pro-democracy movement's tactics illegal, from public gatherings to certain online comments.

That has left demonstrators seeking more creative methods, like supporting sympathetic businesses.

Last week's arrest of pro-democracy activist and media tycoon Jimmy Lai was a case in point.

Instead of flocking on the streets after police frogmarched him in handcuffs through the office of his flagship Apple Daily newspaper and rummaged through files, protesters bought shares of its parent company Next Digital to fuel a 1,100 per cent rally.

They also bought up copies of the paper and encouraged supporters to take out ads.

"Through blood, toil, tears and sweat, we will strive on," read a front-page ad from a university student union.

"However difficult it may be, Hongkongers will eventually restore our city."

The response to Lai's arrest heralded another adaption for a protest movement that has constantly changed tactics since hundreds of thousands of people on the streets first captured the world's attention last June.

The security law prompted some activists to flee the city while others restrict activities due to the risk of spending the rest of their lives in prison.

"The protest movement has been reduced quite a lot," Lai told Bloomberg Television in an interview last week, after he was released on bail.

"Those that remain are still very strong. And more people are reacting to the national security law in a different way," Lai said.

"I think the movement will go on. I don't know how they're going to go on. We can no long have 2 million people walk on the street. Are people going to scatter into small groups? I think in the future there will be innovation."

Lai's trial in a separate case of alleged criminal intimidation against an Oriental Daily reporter in 2017 was scheduled to begin Wednesday morning, but was postponed due to Typhoon Higos.

IMPLICIT SUPPORT

One pro-democracy supporter, a 26-year-old professional who only wanted to be identified by her surname Tsui, said that protesters were concentrating on spending money at so-called yellow businesses that support the pro-democracy movement.

"This is the most basic way to fight the government," she said.

"At the moment, there is no safe activity or protest that we can take part in, so the level of daily activity is very important. No matter what happens, we have to continue to support the yellow economy."

Stanley Wong, an Apple Daily columnist, bought 1.2 million shares of Next Digital to show his support.

But he said it was more practical for ordinary Hong Kong residents to simply shop at stores that support the movement as a form of protest.

Store owners didn't need to risk censure by putting up slogans, he said, but could do something subtle - such as posting pictures online of themselves buying the Apple Daily newspaper.

"They cannot show support explicitly, but they can do it implicitly," he said.

Hong Kong Chief Executive Carrie Lam has defended the law barring subversion, secession, terrorism and foreign collusion as a necessary tool to quell the sometimes-violent unrest that paralysed the city last year and pushed the economy into a recession.

The US, which sanctioned Lam and 10 other officials over the legislation, has called the law an assault on Hong Kong's freedoms.

Some key Hong Kong activists moved overseas in order to keep up the fight and lobby international support, particularly as it's illegal under the law to advocate for sanctions on Hong Kong or Chinese officials.

In the wake of the law's enactment, the UK, Australia and Taiwan all proposed various ways to welcome more Hong Kong residents.

"Having the national security law makes international advocacy work difficult in Hong Kong, so there are more and more people outside of Hong Kong taking up that responsibility," said Nathan Law, a democracy activist who fled to London and recently had a meeting there with US Secretary of State Michael Pompeo.

"As long as we're working on that goal, it's just a matter of division of labour."

'SYMBOLIC ACTS'

Another veteran pro-democracy activist, Joseph Cheng, recently left Hong Kong for Australia.

"People will not bow to this suppression, but they will also be very careful," Cheng said.

"It's natural they don't want to get arrested, and there will be all sorts of innovative and symbolic acts."

In less than two months, the security law has introduced unprecedented restrictions for a city accustomed to regular protests and a free media.

In addition to Lai, prominent activist Agnes Chow of the now-defunct Demosisto party has been arrested.

Others including Joshua Wong, the student leader who came to global prominence during the 2014 Occupy movement, reported being followed.

Veteran pro-democracy politician and lawyer Albert Ho said that activists would need to find new avenues to voice their opposition, like citizens of Eastern Europe under Soviet rule.

Some younger staff at his non-profit, China Human Rights Lawyers Concern Group, have resigned out of fear of being associated with an organisation that has received foreign funding over time, he said.

Still, he expressed hope that protesters would flood the streets again once Covid-19 eased.

"If the virus situation is getting better and the government has no way to refuse marches or protests, again the city will be filled with a million people - people are waiting for that," Ho said.

"Unless Hong Kong is turned into a prison. And then everyone will have to be disciplined, like in mainland China."