And yet we still engage him.

[Acer]

I reserve the right to reply to any post as I see fit, regardless of the troll status.

There is one poster who posts to trigger by reposting the same tired points again and again. I try not to engage unless something new is posted.
There is another who turns every thread they touch into a gun thread, but I don't consider that a troll, just a passionate advocate for a particular cause.
Then there is Speedy, who is playing 4D forum chess while the rest of us are stacking alphabet blocks.