Google Fi, possibly others affected by T-Mobile data breach
Google Fi has notified customers that their primary network provider (T-Mobile,) experienced suspicious activity that contained customer data for Google Fi.
Limited amounts of customer data were exposed . These include SIM Card serial numbers, account status, info about the mobile service plan, activation date. They claim no personal information was exposed.

It appears it’s a fairly limited breach, probably related to the one they just announced. I’m not exactly sure what one can do with any of that info, but it’s probably a pretty good bet that other MNVOs will be announcing the same fairly soon. I know Ting runs over T-Mobile, and I’d bet a lot of others do as well.
At the moment Google Fi says just be aware… nothing you need to do. Wasn’t them or their systems which contain a lot more info.
Remember kids, when you join T-Mobile you get Netflix on us, Apple+, and now it looks like you’re potentially getting lifetime credit monitoring as data breach after data breach keep coming.