Reading this question caused me to wonder: Is it even possible to keep a GPL-licensed software internal to one company?
Am I correct in thinking that any employee who has access to it, would be free to distribute it, either during his employment or after leaving? And also, that GPL specifically forbids stopping such distribution by NDAs and similar means?
So in real world, if one wanted to keep such GPL software internal, access to it would have to be restricted to just a few individuals for have high motivation to stay loyal to the company?