so... they actually allow personel to make a copy for personal use from a not-jet released movie? And then they wonder how these things come up on various download sites?
Why would you give away your life's work to some thieving bastard on the internet who you'd never met and didn't care about you, anyway?
On a large operation you can't rule out the bitter ex-employee factor either.
If you have a guy working for you who would leak something you're working on, the solution isn't to not allow people to take things home, it's to fire people who would harm your company.