I'm quite careful about what I post online and actually have had positive comments in interviews about what people have found having googled my name. I tried putting my screen name (which I believe is unique) into PeekYou and it entirely failed to find my real-name, google searching names is much better to be honest.

Quite simply, the best debugger in the world is another developer that knows the code, and the more people look at the code, the smoother it will run (even if there are some messy bits from too many people working on the same part.) With this in mind, open source should work better because there are far more open source developers and testers than any one company could possibly hope to employ and swear to secrecy about their code.