When I was a kid I played football. My coach used to tell us, "it doesn't matter if he hit you first, or made you mad enough to hit him. Don't. Because the ref is going to see YOU every time."
When I got older, a friend of my father's gave me the best piece of advice I ever heard, "It's not bait unless you bite."
In other words, don't hit back. Don't 'defend' yourself. Let it go. Or if you prefer the 'internet' version, "Don't feed the trolls". Report it. Walk away. Be the bigger, and better person. Save yourself from an infraction (they're hoping your retaliation gets you banned before they do, it's the game they play).
No one is perfect and we all cave to it occasionally, but look at it this way..
- You have to read the post.
- The post has to cause an emotional reaction.
- You have to click REPLY.
- You have to type out your, probably lengthy, response.
- You have to click SUBMIT.
Five opportunities to not take the bait. Even if you exclude the first two, you still have three.