For a look at well known performers who exchange veiled and unveiled insults at each other, check out "An evening you will regret for the rest of your life" with Steve Martin and Martin Short. In their case they are old friends and the insults are part of the performance.

Meanwhile, most folks either know or learn how to act with each other. I agree that context is everything. One of the problems with social media is that a great deal of context gets stripped out of our windows, particularly the setup information that is often not optional, but required.

We are not all acculturated to the internet (yet).