On Wednesday, Amazon.com AMZN.O faced a lawsuit from consumers alleging that the company has been secretly tracking their locations using their cellphones and subsequently selling the gathered data.

A proposed class action suit filed in a federal court in San Francisco claims that Amazon secured “backdoor access” to users’ devices by supplying numerous app developers with a code called Amazon Ads SDK, which they integrated into their applications.

This allowed Amazon to amass a substantial amount of timestamped geolocation information, detailing where users live, work, shop, and travel to, thereby uncovering sensitive details such as religious beliefs, sexual orientation, and health issues.

The lawsuit states, “Amazon has essentially created a detailed profile of consumers without their awareness or approval.”

The complaint was lodged by Felix Kolotinsky from San Mateo, California, who alleges that Amazon gathered his personal data through the “Speedtest by Ookla” application on his device.

Kolotinsky claims that Amazon’s actions breach California’s penal codes and a state law against unauthorized access to computer systems, and is seeking unspecified compensation for millions of residents in California.

Amazon, headquartered in Seattle, has not yet commented on the allegations. The plaintiff’s legal representatives have also not responded to requests for further information.

Concerns are rising among individuals and regulators regarding companies profiting from data collected without user consent from mobile devices.

Previously, on January 13, the state of Texas filed a lawsuit against Allstate ALL.N for allegedly monitoring drivers’ behavior via their cellphones, using this data to increase premium rates or deny insurance coverage, and selling it to competing insurers.

Allstate has stated that its data collection practices adhere to all applicable laws and regulations. Since then, at least eight similar private lawsuits against Allstate have been initiated.

The case is titled Kolotinsky v. Amazon.com Inc et al, U.S. District Court, Northern District of California, No. 25-00931.

Reporting by Jonathan Stempel in New York; Editing by Richard Chang