Previously we show a warning dialog every time the user tries to connect to a host with mobile data. This turns out to be too annoying and people are complaining about it, so we removed it in M70.

However according to this thread:
https://groups.google.com/goi/16806868521449950003/msg/f7iFfs8MqAk/BlGsGLv0AgAJ

It's still a good idea to give user some warnings when they are using mobile data, and it can be less interruptive.

We could do some bandwidth/data usage estimation and show up the warning message (as a toast?) only when the estimation is high, and provide them information about limiting mobile data usage for the app.