Is Google the new Hotel California?

When Google takes new employees on is it like the Eagle's song "Hotel California" in that no-one then ever leaves?

I know Google goes out of it's way to protect its own algorithms but surely some details must get passed out to the wider world? No individual working in a company can be that secretive ALL of the time, can they?

Or is that the team of engineers are broken down so one team does not know what the other team of engineers do - that way limiting damage?

Why has no engineer ever left and set up as an SEO...? I guess either contractual obligations prevent them or the money and kudos of working for Google is just too good to be true!

I'm only curious as many SEO'ers have tried to "crack" Google's algorithms but at best they are only good second guesses or best out of date...

I know Google likes to keep us in the SE world second guessing but at times I think it drives everyone mad.

Cheers

ukdaz