Johnson Yeung had been in police detention for over 40 hours this week when he heard someone shout “Riot! Everyone will get a riot charge!” as they were returned to the block of jail cells.

The building, housing more than half of the 49 people arrested at Hong Kong’s latest anti-government protest on Sunday, was dumbstruck.

“The whole cell was in silence at first and then I started to hear someone from the next cell sobbing,” Yeung told The Independent.

Then came the questions. “People were really worried and there were so many things on their mind: how were they going to tell this news to their family? How are they going to arrange things with their job? What would happen if they lost several years of freedom?”

Many of the protesters, the vast majority of whom are under the age of 25, had been initially told by the police they would face unlawful assembly charges as the protest against the government had not received official approval, Yeung said.

The stakes had changed suddenly as 44 of 49 protesters found themselves charged with the far more serious crime of rioting, which carries a maximum 10-year prison sentence under a colonial-era public order ordinance.

It was a life-changing moment for the protesters but one that also marked a major turning point in Hong Kong’s summer of protest, according to experts, which since 9 June has seen hundreds of thousands of people protest against a legislative bill that would have paved the way for criminal extradition to China.

Aftermath of protesters storming Hong Kong government HQ: In pictures Show all 15 1 /15 Aftermath of protesters storming Hong Kong government HQ: In pictures Aftermath of protesters storming Hong Kong government HQ: In pictures The lobby of the Legislative Council building in Hong Kong is seen covered in graffiti after it was stormed by protesters Getty Aftermath of protesters storming Hong Kong government HQ: In pictures Police officers stand guard at the Legislative Council building in Hong Kong after it was stormed by protesters EPA Aftermath of protesters storming Hong Kong government HQ: In pictures The colonial flag of Hong Kong hangs in the chamber of the Legislative Council after protesters stormed the building Reuters Aftermath of protesters storming Hong Kong government HQ: In pictures Police officers are seen behind cracked glass panels that were damaged by protesters trying to ram their way into the Legislative Council building EPA Aftermath of protesters storming Hong Kong government HQ: In pictures Shattered glass is seen on the outside wall of the Legislative Council of Hong Kong after protesters smashed their way in the building AP Aftermath of protesters storming Hong Kong government HQ: In pictures Riot police patrol the Legislative Council building in Hong Kong after it was stormed by protesters Getty Aftermath of protesters storming Hong Kong government HQ: In pictures Police officers inspect damage to the Legislative Council building in Hong Kong after it was stormed by protesters AFP/Getty Aftermath of protesters storming Hong Kong government HQ: In pictures A caricature of Hong Kong leader Carrie Lam is pasted on a pillar outside of the Legislative Council after protesters broke into the building Reuters Aftermath of protesters storming Hong Kong government HQ: In pictures Graffiti is seen in the chamber of the Legislative Council in Hong Kong after protesters stormed the building Getty Aftermath of protesters storming Hong Kong government HQ: In pictures Abandoned placards and litter is seen outside the Legislative Council building in Hong Kong after a protest on July 1 EPA Aftermath of protesters storming Hong Kong government HQ: In pictures A painting hung i the Legislative Council in Hong Kong is covered in graffiti after protesters stormed the building Getty Aftermath of protesters storming Hong Kong government HQ: In pictures A lift in the Legislative Council building is seen covered in graffiti and litter after protesters stormed the building Getty Aftermath of protesters storming Hong Kong government HQ: In pictures The chamber of the Legislative Council in Hong Kong after protesters stormed the building Getty Aftermath of protesters storming Hong Kong government HQ: In pictures A desk in the chamber of the Legislative Council in Hong Kong is covered in graffiti after protesters stormed the building AFP/Getty Aftermath of protesters storming Hong Kong government HQ: In pictures An area inside the Legislative Council building complex is strewn with litter and smashed glass after it was stormed by protesters Getty

Although the bill has been suspended, the protests have shown no sign of ending. Residents are still deeply angry at the government’s failure to establish an independent inquiry into police use of force and fully withdraw the bill despite popular protests.

Now protesters could find themselves facing a new threat in the form of rioting charges if they attend any “unlawful assembly” – regardless of whether they personally clash with police at increasingly fraught and violent demonstrations.

“People in Hong Kong think as long as you don't act violently or disorderly you may be safe from being charged with rioting, but indeed not,” said Billy Li, a convener of the Progressive Lawyers Group.

“What makes a riot is if anyone within an unlawful assembly breached the peace – then everyone within that unlawful assembly will become a participant of a riot.”

Such “illegal assemblies” may also be on the rise as well as police have declined yet another march scheduled for this weekend in Mong Kok – the third such action in recent weeks, according to Hong Kong Free Press.

Once a riot is declared, charges could seemingly be laid on anyone from a volunteer medic on the scene to a peaceful protester standing at the perimeter, far away from police and protester clashes. Disproving such charges could take months if not years of legal time and fees.

While protesters have come to expect criminal prosecution since the end of 2014’s Umbrella Movement democracy protests, the charge of rioting has been seldom used until recently.

The ordinance was enacted during Hong Kong’s deadly 1967 Cultural Revolution-inspired riots but it was rarely if ever used by the British colonial administration afterwards, according to the city’s last UK governor Chris Patten.

The charge of rioting has made a return, though, since the failure of Hong Kong’s 2014 democracy protests, most noticeably at localist-tinged protests in 2016 and again at an anti-extradition protest on 12 June.

One reason may be that the anti-extradition protests, unlike in 2014, lack a central leadership, such as activist Joshua Wong, who police can arrest to send a message. Instead, the vast majority of protests have been organised over social media in a decentralised and democratic manner, making them far more difficult to control.

Willy Lam, an adjunct professor at the Centre for China Studies at the Chinese University of Hong Kong said the use of such mass rioting charges was a sign that authorities were escalating their tactics.

"The fact they decided to lay this charge relatively quickly and on a relatively large number of people shows that the authorities seem to be ‘fighting back,’” Lam said.

He speculated that the shift in tone was at the order of Beijing, not Hong Kong’s local government, as leader Carrie Lam is widely believed to have lost her authority in light of the protests and has rarely been seen in public in recent weeks.

The charges also come the same week that China’s military released a promotional video of soldiers firing onto the streets of Hong Kong and rounding up civilians. The intent, Lam said, is to have an overall “psychological” impact on protesters’ morale.

The fact they decided to lay this charge relatively quickly and on a relatively large number of people shows that the authorities seem to be ‘fighting back' Willy Lam, professor at the Centre for China Studies

News of the charges on Tuesday night drew yet another round of protesters to the streets but the impact has been felt beyond the general public.

A civil servants’ protest was planned for Friday night and an anonymous online letter from Department of Justice employees has questioned Secretary for Justice Teresa Cheng’s mass use of rioting charges and her professional judgement.

“Cheng has poor personal conduct and is not an expert in criminal law. When handling cases involving large-scale public events, she mainly considered political factors, and insisted on prosecution when there was not adequate evidence, no reasonable prospect of conviction, or when it was not in line with public interest, treating the prosecution code as trash,” the letter said, according to a translation by Hong Kong Free Press.

Hockey match turns into brawl between Hong Kong and Chinese teams over political turmoil

Many of the protesters charged with rioting are restricted by a curfew of midnight to 6am, meaning they can still take part in protests as long as they are during the day – but not into the more intense late night demonstrations that often end with intense police standoffs.

Yeung, who is facing obstruction charges, does not have to abide by the curfew but he nevertheless has a difficult road ahead – a fate shared by the rest of Hong Kong.

He said that escalating police and prosecution tactics would likely only inspire more protests. The only way forward, he said, would be to reverse course completely.

“The Hong Kong government has reached the status where they cannot govern society right now.

“The reason is because the Hong Kong government refuses to engage in reconciliation and also to take concrete steps to resolve this political crisis.