[CamperBob2]

It's possible that's exactly what it is, in a cultural-transmission sense.

(Suggest discussing this one, rather than reflexively downmodding. The use of sarcasm and mockery as legitimate rhetorical tools has previously been brought up by people like Sam Harris. I thought it was a pretty interesting point when I first encountered it.)

[TeMPOraL]

I agree. The whole concept of memes that evolve and spread like genetic material is a useful tool (hell, that's where the 'viral' comes from). It's useful to talk about memetic immunity in individuals and groups. If sarcasm helps you defend against harmful memes, then that's exactly what it is - a vaccine.