In terms of civility, I feel that respect should exist on both sides, if trying to argument or convey a point. There's an important distinction, though. If you're talking with someone about something that directly affects them while you're on the other side, it feels and is different. For example, if you're talking with a Latinamerican about what recently happened in Venezuela, your "argument" feels pretty much like an attack filled with hate, while on the receiving end that impoliteness towards this person is more about frustration and a negation of the whole reality they're living. Violence by oppressors is hate, violence against oppressors is liberation. Of course no one is going to topple the US empire discussing online, but to illustrate my point a bit.