Comment 55 for bug 191889

Yeah, what Dan said. If you're going to tweak the default settings to be outside of the use case, there's going to be more than simply Firefox which is going to be affected. Other system services are moving to use NM to determine on/off state, and you're expected to disable NM if you aren't going to use it for every device.

I'd recommend a release note reminding people that they should disable the NetworkManager service if they are managing network connections by hand.