A Chinese man was arrested in Yixing county, Wuxi, in Jiangsu province on Thursday after he has allegedly spread misleading information about an anti-prostitution operation.

The man allegedly posted a message with two screenshot images on weibo, claiming that the Jiangsu security bureau had been using big data technology to detect who paid for prostitution. He said the police bureau in Yixing recently asked 1,200 suspects to report to the police station over alleged prostitution.

According to the weibo message, Yixing police shortlisted the people who used a QR code to transfer more than 600 yuan (US$89) at certain sauna clubs. Apparently, he said, some people received a phone message asking them to report to the Yixing police station because they were allegedly in violation of Chapter 82 of the Public Security Administration Punishment Law of the Peoples’ Republic of China.

He claimed the message urged recipients to explain their cases, which may influence whether they were penalized for their offense. Otherwise, they would be arrested if they do not report and ignored the messages.

The man’s post sent shockwaves through a large section of the male population of the province, who were concerned that the police – for the first time – were using big data to make arrests, especially after a lot of mainland media reported the same thing on Wednesday.

The internet lit up with discussions on how people could avoid getting caught in the future. Among the suggestions were splitting the bill into two transactions, or simply paying cash, the more common way of paying for such services.

On Wednesday evening, Yixing police tried to play down people’s fears. They told the mainland press that the people who received the phone messages were only asked to report – and whether they would be charged depended on the evidence.

A police statement said officers had been tracking prostitutes’ clients after a prostitution ring was busted and 15 people were arrested on January 21, 2019. They warned the public not to spread misleading information about the case.

On Thursday, the police bureau said in another statement that it had arrested the man who allegedly made the two screenshot images and posted the warnings. In a letter of apology, the man said he made up the figures of the number of targeted suspects and the 600 yuan threshold.

He said he thought it was an attractive headline on social media. He is now detained by police.

However, it is still unclear whether Yixing police had used big data and QR code transaction records to identify prostitutes’ clients. The incident certainly set alarm bells ringing with many who thought there was no risk in paying prostitutes or doing illegal activities with mobile payments in China.