Not entirely surprising really. Zynga makes no secret [1] of the fact that they don't actually design anything. They are very clear about the practice of copying [2] whatever is popular, slapping their own name onto it and peddling it off as their own.

And to top it all off, they then proceed to sue [3] the pants off of anyone trying to do the same.

[1]: http://www.geek.com/articles/games/zynga-ceo-to-employees-st... [2]: http://www.businessinsider.com/how-zynga-is-just-like-micros... [3]: http://www.google.nl/search?q=zynga+lawsuits