Wow, I actually searched the page once for license information a couple of years ago. Did that change (I guess not)? Plus, we had some OSS legal consultant that told us, SO falls under copyright laws and we must not copy/paste anything because of legal issues...
So, thanks a lot for correcting my statement, that’s very important!
Sebastian Baltes has a couple of links about this below that I thought were interesting:
You may find our article about Stack Overflow code snippets in GitHub projects interesting, which has recently been published in Springer's Empirical Software Engineering journal . Beside some information about Stack Overflow's license, we report on an online survey with developers about their awareness regarding Stack Overflow's licensing and its implications (spoiler: they are often not aware of the implications). I also wrote a blog post  summarizing some of the results.
We’re a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.