Mark Kaplan has assembled a fine collection of rhetorical shenanigans (he calls them "tools") from which I'd like to offer the "Rhetorical Trick of the Day." I very much agree with the epigraph on his site—

"..the knowledge of rhetorical forms by the listener can in fact jeopardize the effect the speaker hopes to arouse with those forms, in that the effect is subjected to the listener's control"

These "tools" are frequently used in the Comments section of blogs and especially among the ideologically committed of whatever persuasion. If you think of (or spot) additional "tools," please share them so that we can add to the list.

Psychologize: If your opponent criticises you more than once, he is evidently obsessed/fixated by you. You are being stalked by him, and his objections are to be reread as ‘symptoms’ of his disorder. [edited]

Random example drawn from Google: I'll type slowly so you can follow along. You seem to be obsessed with cyber-stalking Ethan's blog. You claim to despise him and his topics, yet you continue to show up here. Why? Are you that desperate for attention? Did mommy not hug you enough as a child? If you don't like this blog, stop showing up!