You cannot. When I worked at Apple, we had an intern on our team who told me he hated everything about Apple, and that he used Linux for everything. When I aske

You cannot. When I worked at Apple, we had an intern on our team who told me he hated everything about Apple, and that he used Linux for everything. When I asked him why he worked at Apple for the summer he said "To learn the enemy". He had access to a fairly significant amount of source code. It would have been trivial for him to copy a lot of this onto a USB stick. I have no evidence that he ever did this. Our team was great, though, so I hope that by the end of his internship his attitude had changed.