How to stop programmers to copy the code from GitHub when they leave the company?

Question

A friend of mine owns a tech-company and he said that one of the biggest problem he faces is that when a programmer leaves the company, they somehow, copy and share the code with their personal GitHub account. What preventive measures can be taken in this regard? The whole code resides on GitHub.

Answer 1

It does not matter where their code comes from. They can as easily copy it to a USB Disc, or CD, or whatnot, and then put it on github later. Or put it in any other location, Bitbucket, filesharing, etc. This really has little to do with github.

Common protection actions are making employess sign NDAs, have license headers in all files, and have a legal department tracking copies.

It's no different from protecting movies of videos from being provided free on the internet.