Chinese Police are Using Cellphone Data to Track Down Protesters

CNN reports on the aftermath of last weekend's protests against the Chinese government:

A protester told CNN they received a phone call Wednesday from a police officer, who revealed they were tracked because their cellphone signal was recorded in the vicinity of the protest site.... When they denied being there, the caller asked: 'Then why did your cellphone number show up there?'

In China, all mobile phone users are required by law to register their real name and national identification number with telecom providers. The protester was also told to report to a police station for questioning and to sign a written record....

In Shanghai, where some of the boldest protests took place with crowds calling for Xi's removal on two consecutive nights, police searched residents' cellphones in the streets and in the subway for VPNs that can be used to circumvent China's internet firewall, or apps such as Twitter and Telegram, which though banned in the country have been used by protesters. Police also confiscated the cellphones of protesters under arrest, according to two protesters who spoke to CNN.

A protester who was arrested over the weekend said they were told to hand over their phone and password to the police as 'evidence.' They said they feared police would export the data on their phone after it was confiscated by officers, who told them they could pick it up a week later. Another protester said police returned their phone upon their release, but officers had deleted the photo album and removed the WeChat social media app.

One protester told CNN they successfully avoided being contacted by the police as of Thursady afternoon.

During the demonstration, they'd kept their phone in airplane mode.

Read more of this story at Slashdot.