[alex23478]

> only runs when a device is connected to Wi-Fi or Ethernet. Cellular bandwidth is never used.

This cannot be guaranteed.

They seem to use the NetworkInformation API, which as of now is declared as experimental and straight up does not work on Firefox or more importantly on Safari (and therefore the whole iOS browser ecosystem). Apart from that, they're using IP ranges of mobile carriers for detection. [1]

So let's say you're using iOS and a VPN while on the go. This will use your mobile data unless you're using an adblocker (since their service is only opt-in if you're using an adblocker) [2]

[1] https://github.com/easylist/easylist/issues/7872 [2] https://github.com/uBlockOrigin/uAssets/pull/8874#issue-6142...