Answering questions the OP has asked elsewhere

Question

I recently found this question here, and when searching for something else on SO, this same question. The OP has simply asked the same thing on two separate sites, at exactly (roughly) the same time.

I've seen this a couple of times, and been voting down (simply because it's time-wasting). But since one of the purposes of the SE sites is to produce knowledge, would it be ok on these types of questions to, in addition to posting an own opinion, quote answers from the SO questions?
I mean, it solves the question, but it does feel like ripping off other users ideas.

Answer 1

It is seriously frowned upon to cross-post questions.

It is OK to pick one site, go for it, and if you don't get a good response, then ask again on another site.

Even then, we believe the question must be reformulated and tailored to the specific audience.

In other words, say you have a question about going downhill really fast on snow -- you would ask very differently depending on whether you were talking to an audience of skiiers vs snowboarders.