"Keyboard Warrior"
"1. A Person who, being unable to express his anger through physical violence (owning to their physical weakness, lack of bravery and/or conviction in real life), instead manifests said emotions through the text-based medium of the internet, usually in the form of aggressive writing that the Keyboard Warrior would not (for reasons previously mentioned) be able to give form to in real life."
I don't tend to take lessons from Urban Dictionary but can understand why Arsenal fans, sponsored by Google Search, would.
The argument was done with, moved on, I was discussing the game, in the LFC thread with a United fan and you chose to re-ignite it. You're either a keyboard warrior or a troll and possibly both.
You can carry on trying to provoke me into saying something that gets me a wrist slap or you can grow up and move on.