A very noticeable increase in security on the streets of Beijing’s financial district was reported on Monday. Chinese social media buzzed with video clips of unhappy investors loaded into buses and carted away by police.

According to Reuters, the unfortunate passengers on those buses included many people who invested in collapsing peer-to-peer (P2P) lending schemes. Reuters reports:

P2P platforms collect funds from investors promising attractive returns. The funds are in turn offered to borrowers traditionally not served by risk-averse banks.

The number of online P2P platforms has shrunk dramatically in recent years as Beijing has cracked down on risky lending practices in a broader deleveraging campaign.

Ezubao, once China’s biggest P2P lending platform, folded in 2016 after it turned out to be a Ponzi scheme that collected 59.8 billion yuan ($8.7 billion) from more than 900,000 investors through savvy marketing.

By the time police made arrests in early 2016, the company had failed to repay 38 billion yuan.

The Financial Times postulated the Chinese government wants to head off angry protests against regulators as a wave of defaults in the P2P industry wipes out the investments of countless families. According to the Financial Times:

The surge of discontent over P2P losses has highlighted the way in which risks in the Chinese financial system could potentially translate into more widespread unrest. Many who lost money are now questioning why the platforms were allowed to portray themselves as government-approved, and why local authorities could not do more to recover their savings.

Ms Chen, a single mother who had invested almost all her family savings in P2P platforms, said that she had expected many more protesters from her various social media investor groups to show up. According to social media posts, police had stopped P2P protesters at train stations and airports across the country from traveling to Beijing over the weekend.

Ms. Chen pronounced herself “alarmed” to see so many police officers swarming the Beijing financial district. Her alarm proved to be justified as a squad of police officers descended upon her, determined she was a P2P protester, and promptly removed her from the area. Would-be demonstrators who didn’t leave quietly were dragged away by the police, who were not keen on having the proceedings photographed.

“Teams of police and security guards were gathered at every corner of the intersections near the offices of banking and securities regulators, as well as at the entrance to the underground train stop for the financial district. They checked the identity cards of everyone entering the square kilometer that is home to Beijing’s domestic and international banks,” the Financial Times reported.

One aspiring demonstration organizer told the South China Morning Post (SCMP) at least eight thousand angry investors made it to Beijing, but only a few hundred made it to the China Banking and Insurance Regulatory Commission headquarters, and they were effectively swept from the streets by lunchtime on Monday. Some spoke of being forced onto buses and sent back to their hometowns by police, while others were dumped into temporary holding facilities and threatened with the loss of their jobs unless they quietly returned home.

“The grievances come at a particularly delicate moment for the authorities in the world’s second-largest economy, occupied as they are with handling the fallout of a trade war with the United States,” the SCMP noted.

Trouble in China’s “shadow banking” grey market has been predicted for years. In order to keep the reported level of consumer debt low and maintain its image of carefully calculated borrowing primarily for essential infrastructure projects, the authoritarian Chinese government tolerated a large number of dubiously legal and largely unregulated lenders and investment houses. The Chinese citizens who poured money into these enterprises believed their investments were guaranteed and the shadow banks were relatively stable.

Peer-to-peer operations represent a $200 billion slice of a much larger shadow banking pie. It has been speculated that even China’s micro-managing political elites don’t know the true size of the shadow market, and they didn’t really want to know. The government was eager to count the benefits of shadow banking without acknowledging the risks.

As the SCMP report implied, China’s trade war with the United States might have triggered the long-feared cascade collapse of these murky lenders and investment houses. The rate of collapse accelerated to breathtaking speed over the past two months, according to SCMP:

A total of 165 lending platforms stopped letting investors withdraw from their accounts in July, as a financial crackdown sucked up cash, affecting their ability to honor redemptions. Some proprietors also disappeared with their investors’ money. The number of cases jumped to triple digits last month, from 65 cases in June, and 10 in May, according to statistics by Wangdaizhijia, a data provider on China’s online lending business.

The delicate state of shadow banking is exemplified by the case of 28-year-old Yao Kunjie, CEO of peer-to-peer lender Beimi Wallet. Yao made the Forbes list of “30 Under 30” standout young Chinese entrepreneurs this week … just a few days after he was released from jail in Shanghai, where the authorities suspect him of “illegally absorbing public funds or fundraising fraud.”

Beimi Wallet investors suddenly find themselves having trouble accessing about $650 million in deposits.

“The company statement said it was cooperating with police and there was no plan to repay investors until all asset claims had been verified. Earlier, Beimi said it hoped to gradually pay back investors,” the South China Morning Post reported on Saturday.