The Federal Trade Commission has ordered Google to pay $19 million (about £11.6m) to those whose children mistakenly bought in-app purchases.
This covers purchases made back from 2011, when in-app purchases were first introduced on Google's service. The FTC deemed these a violation as they were a commercial practice that charges consumers for purchases made by their children.
The FTC initially took issue with Google's failure to ask for a password or proper authorisation when buying in-app purchases. Google then added a password verification screen in 2012, but this failed to note the exact amount the transaction would be, and worse, that all transactions would remain accessible without re-entering a password for the next half-hour.
"For millions of American families, smartphones and tablets have become a part of their daily lives," said FTC chairwoman Edith Ramirez. "As more Americans embrace mobile technology, it's vital to remind companies that time-tested consumer protections still apply, including that consumers should not be charged for purchases they did not authorise."
Back in July, Google removed the "free" label from free-to-play games in compliance with the European Commission's recommendation that it makes these sorts of things clearer.
In January, Apple had to pay back $32.5m (about £19.9m) over basically the exact same thing. The FTC likewise filed a case against Amazon for its similar practices back in July. That case is still ongoing.