On Sept. 2, the first day of the academic year in Hong Kong, thousands of high school and university students did not attend class.
Instead, crowds of students braved stormy weather to participate in a class boycott as part of the ongoing anti-government protests. Since then, they have continued to routinely skip classes — in the name of democracy -- while the protests in the former British colony have reached new levels of violence in recent days.
But now, some student activists are feeling the need to catch up on their academics, and they're turning to the same encrypted messaging app that helped organize and coordinate the protests: Telegram.
Carrie, 17, who attends a public school in Hong Kong, told NBC News she joined a fast-growing network of channels and group chats on Telegram dedicated to virtual tutoring after devoting her time over the summer to the demonstrations. The largely student-fueled movement began in June over a now-withdrawn bill that would have allowed suspected criminals to be extradited from Hong Kong to mainland China.
"I spent the entire summer making posters and distributing leaflets about the anti-extradition bill movement, and I was scrambling to finish my summer homework before the start of the term, so I decided to join the group chats to seek some urgent help," she told NBC.
An encrypted app which permits the creation of group chats and channels, Telegram has become wildly popular amongst the city's young, digitally savvy protesters who use it to swiftly share sensitive information and reduce the risk of surveillance by authorities. Details on upcoming rallies, safety tips, and even information about undercover police are quickly shared to thousands of subscribers on the popular app, with one of the largest channels boasting more than 270,000 subscribers or approximately 3.6 percent of Hong Kong's population.
But as protesters turn to Telegram for more than just organizing, they're also at risk of efforts to infiltrate their groups given the movement's reliance on the app, even though it is seen as less risky than other popular messaging apps like WhatsApp.
Hong Kong's monthslong protest movement has taken a dark and violent turn in recent days, with a man being doused with a flammable liquid and set on fire after confronting protesters, and a graphic video that surfaced Monday purporting to show a police officer shooting a protester at point blank range in broad daylight. The first official protest-related death was also reported, when a student fell off a car park building near a police dispersal operation last week.
This week, universities became a new battleground, including one of the semi-autonomous territory's most prestigious: The Chinese University of Hong Kong. It was at the epicenter of a fierce standoff between police and protesters that led to the campus being engulfed in smoke as protesters hurled petrol bombs and used impromptu weapons against police, who fired volleys of tear gas. University officials, citing safety concerns, cut the academic semester short for undergraduates and postgraduate students, while some other leading universities announced a move to online teaching for the remainder of the term.
Worries over the infiltration of Telegram groups by what some protesters refer to as "police spies" has led to group chat administrators choosing to shut down chats altogether or banning group members from sending any messages. Protesters fear the groups are being monitored by members of the Hong Kong police force and potentially by China, and that their participation may be used against them in the future.
Although there is little evidence of this, news reports have circulated about a pro-Beijing Telegram channel that encourages its thousands of members to submit photos of protesters to a Chinese government website.
In June, a 22-year-old student named Ivan Ip, who also served as an administrator of a Telegram group chat that had more than 30,000 members, was arrested on charges of public nuisance.
"We take extra care in vetting people interested in joining our chats, to make sure they are actually students and we ask for ID submission," said Ginny, an English tutor and administrator for an academics-focused group chat that has more than 900 subscribers.
Carrie and Ginny, like the other students and tutors who spoke with NBC News, asked that their last names be withheld due to concerns about the repercussions of publicly discussing their support or participation in the protests.
A small but growing number of students are leaning on the popular messaging app for academic help as they skip crucial lectures and homework assignments.
Help comes in the form of dozens of channels and group chats focused on a variety of topics, organized by an initiative that translates in English as "You Ask, I Answer."
Powered by hundreds of volunteers, it provides a fast-growing base of nearly 4,500 subscribers with online tutoring and content on well-established school subjects including history, economics and English.
"I ask questions about my studies and also about university enrollment, and I always get feedback," Carrie said. "The teachers are willing to spell out the answer for me until I get it right."
"Once, there were several teachers online trying to answer my questions simultaneously."
She now turns to the channel regularly either for gaining a better understanding of her business accounting and finance coursework or for help on exam preparation.
"I was worried that the protests would affect my academic results, so I joined," said another teenage student, Thomas, who attended the inaugural class boycott.
"It helped me by explaining concepts which I found difficult to understand," he said.
For those outside Hong Kong, Telegram may seem like an unlikely resource for school tutoring. But for students and protesters in Hong Kong, Telegram is a familiar online apparatus because it played a critical role in organizing the monthslong protests
"It was a natural extension," Ginny said, adding that chat administrators maintain a 10:1 student to teacher ratio as much as possible.
"You Ask, I Answer" was created by a 20-year-old university student majoring in education known only as "The Boss" to his team of tutors and chat administrators.
"Frankly speaking, we won't know for sure what will happen to those kids. Worst case scenario, they get kicked out of school because of their participation in the protests. But if they are still willing to study and earn a good grade in their public exam, they can still have the privilege to strive for a better future," The Boss said in an interview via Telegram.
He said he was involved in the recruitment of more than 450 current or former teachers who volunteer their time to tutor students on the platform.
"There is no office. 'You Ask, I Answer' operates entirely online," Ginny said. "We don't really know who the kids we teach are. We don't even know who the other teachers are, and we have not met the founder either."
These Telegram tutors also drill students for Hong Kong's notoriously high-pressure DSE exam, a key requirement for entry into local universities that students take in their final year of high school.
Carrie said she hopes to attend more student strikes or class boycotts. But before she can go out on the streets to help persuade the Hong Kong government to take on reforms, she first has some convincing to do in her own household.
"I have to see if my parents allow me," she said. "They're afraid my school will punish me for the class boycotts. And we never see eye to eye on all political matters anyway."