Yes, 100% legal.
We follow all rules to be legal:
We did our best to give all possible attribution but If we missed one, just let us know, and we will fix this issue ASAP: firstname.lastname@example.org
We did it because not everyone speaks English!
When someone that speaks French or Spanish search for something in his mother language, they often don’t find as many resources as we find in English.
Stack Overflow cannot translate their content
However, our website doesn’t have this kind of restriction.
Even more, all our questions/answers are found on Stack Overflow!
We all know Stack Overflow when it’s time to find an answer to our question. But there is not only Stack Overflow that exists! There are blogs, videos, other forums, and even Stack Overflow in other languages.
Our long-term goal is to create a Knowledge Base with everything we can find on the web that will stay 100% legal