Sometimes, the angry rejoinder falls flat. When it's obvious that they have read a different article from the one you actually wrote. When they don't bother with engaging your argument at all, just take the opportunity to stomp with their hobnails. When they think they're being clever and all they're doing is showing how clueless they are. When they think they're being devastating when you really don't give a rip what they say. Sometimes the angry post is so over the top, you just have to laugh at it.
Now, sometimes, the angry rejoinder would have stung if it had been made a while ago, but by this point you're just over it. You've moved on. So you feel no need to respond. And then there are the times when you'd like to respond, but you realize it would just feed the other guy's response. So, though something in you hates to give an obnoxious someone else the last word, you realize that there is no upside to feeding the trolls. Just move on.
The peace of God is more than just moving on in the midst of internet flame wars, but it is at least that.