[pmontra]

Well, that's risk mitigation.

However if a file touches a developer's machine it can be breached from there unless they do like banks with sensitive information: no internet, no USB, no anything. Kind of impossible to develop like that.

So... IDEs in remote desktops and local browsers to lookup for documentation on the internet? But then you still have to protect against screenshots of code and OCR. Or photos. You can't defend against everything because developers must at least read the code. It's like DRM for music and movies. There is always a loophole.

So, mitigation. If your customers pay for that, good for you. About me, I prefer a local/remote repository for my projects. My customers decide what they prefer, currently git but they don't have many alternatives.