...commenters, that is:
"That artwork is not good, but if it is, it's something I did back in the '90s, with much lower bandwidth."
"You're a troll, and if you're not a troll you are posing as one for some perceived strategic advantage."
"You suck, and I would really like to buy you a beer sometime."
(based on actual online conversations with the regular commenters on the Rhizome.org chatboards)
Update: some revisions to make quips snappier.