Does this mean that one Googler could checkout the complete system, and sell it or put it online? How many people have access to the complete repository? How big is one checkout?
Almost all engineers have access to the "complete system," which is really Google's server-side software. Other repos like Android have historically been more locked-down, but there's been some recent effort to open them up within Google.
Presumably if you tried to copy all of the files, you'd first be rate-limited, then get an access denied, and lastly a visit from corporate security. I wouldn't want to try.
And there's no way it'd fit on a single hard drive.
We wanted to send them a script to help with the conversion process and they flipped out and told them not to send them any code until we become authorized in some special capacity.
They then decided to tell us how a week or so before a coworker sent himself some code so he could work on something from home (according to him at least), and within 20 minutes of emailing himself that code security was already escorting him out the door.
That's 20 minutes for automated filters to catch it, security to review it, HR to process the termination paperwork, and security to go to his desk to escort him out.
Generally, you don't checkout all code you're using, just what you modify. You work in repos that exist virtually, because checkouts would be huge.