If you're working with more than a couple of people it can be worth running an audit on your code, including the libraries you're using. Even if the libraries themselves have permissive licenses, they may inadvertently include bits of SO code.
Wow..that seems much more restrictive than it should be.
They're seriously saying closed source software companies can't use content on Stackoverflow? What if I write a piece of closed source software while consulting SO, is that my own work or a transformed version of the work on SO?
I don't know if that license would really stand up in court, I think a good attorney would have some interesting attack possibilities given the origin of some code you see on Stackoverflow anyway. Not to mention that license is not readily apparent to people, on a social site where you are sharing answers between people does every person in the conversation know what license they are entering in to? How is stackoverflow marketed to people, is that marketing at odds with the assumed license?