Baidu is being sued over allegations of spying on its users—the latest sign that Chinese citizens are beginning to question surveillance.

What's happened: A consumer protection group in eastern China has sued Baidu for collecting personal data without consent. According to the group, two mobile apps developed by Baidu (a search app and a browser) can gain access to users’ messages, contact lists, location services, and phone calls without their consent. Baidu denies the claim.

The bigger picture: Surveillance technologies that make use of highly personal data, such as facial recognition, have become pervasive in China with little public debate. Last week, the New York Times reported on a series of privacy outcries involving Tencent and Alibaba. The Baidu news is the latest sign that things may be starting to change.