Really? The only places I've run into regulatory requirements for audit logs of seeing data is when the data itself is sensitive government data or is legally protected personal data; outside of national security, those aren't the kind of things that generally apply to code (and in the national security space, I'd imagine that you'd need more comprehensive monitoring of your systems, desktop or server, such that using centralized VCS for the purpose would be redundant [alone, centralized VCS for that purpose has holes big enough to drive a truck through, since it can't monitor who sees information once it is checked out, only who checked it out].)