I think that would make disagreement too easy and impersonal. If you disagree, you should confront that person civilly, with a coherent argument, not just click a button at them. Besides, what if they edit their post later to reflect the truth?
EDT: Not that there haven't been moments when I...
Enh. Google can be extremely helpful. I'm not talking about easily accessed sites like Wikipedia; I'm talking about people like casportpony, who'll take the time and mental effort to wade through a dense scientific article and bring forth useful information to share with us lazy slackers (or...
I also would like to see an "educational" reaction. I've seen a few posts be really funny and get a lot of likes, but they don't actually contribute to a thread. And sometimes, they kind of hijack said thread.
Kiki's Balut thread is the sort of thing where the whole thread is an experience...