A Google News bug is causing the app to download tons of data in the background and causing overages for many users. Although the first person to complain about the issue did so on September 1, it isn't until the 19th that the reports started multiplying. Some users are fortunate enough to have noticed it when it had only used 1.3GB of their data; others weren't just as lucky.
There are reports of the app gobbling up 18GB, 20GB, 23GB, 24GB on two devices, and even 28GB in a single night. This is causing overage charges upward of $96 and, for one unfortunate user, it happened while roaming. Google has acknowledged the issue on September 19, and aside from asking a few questions to try to narrow down the issue, nothing else has been done about it. The reports are coming in still.
If you have Google News installed on any of your devices, go to Settings> Data Usage, and disable Background data. Even if you haven't been affected by the bug, it's better to be safe than sorry. This way, the app will only refresh when you launch it and won't burn through a lot of background data.
News Source: Android Police