I do the opposite to the CC, I usually discuss their points calmly and rationally until it becomes evident to any reader following the comment thread they're absolutely batshit and non-sensical. I see it as a public service.

Such attacks often begin with.... 'you're clearly an X' - to which I reply, 'says who? not me, I'm a Penguin'. At which point they have to paint the identity they want on top of my aquatic persona as its the only way to make their points valid. Nothing frustrates the identity-politics armchair philosopher more than someone who lacks an identity and refuses to provide one on request and take their rightful place in the oppression pyramid. :o)