I've seen people say this a few times, and I think it is attacking a misreading of the comment (snarkily, to boot). Charitable interpretation: In a discussion,

I've seen people say this a few times, and I think it is attacking a misreading of the comment (snarkily, to boot). Charitable interpretation: In a discussion, if someone says "Citation needed", it means "I'm skeptical and I'm asking for a citation" (which is quite reasonable), not "You should have supplied a citation before I asked for it" (which I would agree is unreasonable for statements one doesn't expect to be contentious).