Questions & Answers are licensed under [Creative Commons Wiki][1] with Attribution Required license. 

[As Jeff had written:][2] 

> So let me clarify what we mean by attribution. If you republish this content, we require that you:

>  - Visually indicate that the content is from Stack Overflow, Meta
> Stack Overflow, Server Fault, or Super User in some way. It doesn’t
> have to be obnoxious; a discreet text blurb is fine.
>  - Hyperlink directly to the original question on the source site
> (e.g., https://stackoverflow.com/questions/12345)
>  - Show the author names for every question and answer
>  - Hyperlink each author name directly back to their user profile page
> on the source site (e.g.,
> https://stackoverflow.com/users/12345/username).  Furthermore, the links must not be nofollowed.
 
Since Answer Leaks is respecting all the above conditions, it is abiding by the user contribution license and not doing anything illegal. 

As Jeff mentions: 

> I hope that clears up any confusion — feel free to remix and reuse to your heart’s content, as long as a good faith effort is made to attribute the content!


  [1]: http://creativecommons.org/licenses/by-sa/3.0/
  [2]: http://blog.stackoverflow.com/2009/06/attribution-required/