Google has been hit with a US$314.6 million (A$470 million) penalty after losing a major class-action lawsuit in California over its handling of Android users’ mobile data.

The lawsuit, filed in 2019 on behalf of roughly 14 million Californians, accused Google of collecting and transmitting user data from idle Android phones without consent, using mobile data that users were paying for.

The jury found that Google’s practices amounted to unauthorised data use that ultimately benefited its advertising and mapping services.

The court heard that Android devices sent data to Google servers even when phones were not in use and not connected to WiFi, effectively using consumers’ mobile plans to support Google’s backend operations.

Google denied any wrongdoing, arguing that the data transfers were essential to ensure device functionality and were covered under the company’s privacy policies and terms of service.

A spokesperson said the verdict “misunderstands services that are critical to the security, performance, and reliability of Android devices,” and confirmed Google plans to appeal the ruling.

“This ruling is a setback for users,” the spokesperson added, noting that the data usage in question was minor, less than the data required to send a photo.

Lawyers for the plaintiffs hailed the decision as a landmark win for consumer privacy. “This verdict reflects the seriousness of Google’s misconduct,” said attorney Glen Summers.

This case is one of several ongoing challenges to Google’s data practices. A separate class action, representing Android users in the other 49 US states, is scheduled for trial in April 2026.