I think in the case of a rebuttal, particularly when the original statement didn't provide any source, it is a useful practice to provide some type of source -

I think in the case of a rebuttal, particularly when the original statement didn't provide any source, it is a useful practice to provide some type of source - even if was a simple reference. eg 'wikipedia' or '1st result on google!'. Otherwise it's just a really uninteresting he-said-she-said back and forth, no? I really don't think every statement of fact needs references - this isn't scientific paper writing. But where someone is calling out something specific as incorrect, I think its often worth a little bit extra effort to avoid things degenerating into something not much more interesting than name calling. That said, neither of those folks owe me anything. :) I'm just happy I get to learn new things once in a while on HN.