Source code protection at Microsoft

Here's another question about source code protection... So far I haven't been convinced with the answers to similar questions found on this site (NDAs on the legal side, trusting employees vs. protected code, etc.) So I'd like to formulate it in a different manner:How do large companies do to protect their source code? E.g. I have never heard that the Windows, MS-DOS source code was ever stolen, reverse engineered? What steps does a large company like Microsoft take to protect their code?...Read more