if you are worried about people ripping your ideas, make two copies of the DVD and send one to yourself by Recorded or Registered post (something that you have to sign for).
When you get it, dont open it and keep it safe. Then in the future if you ever feel that you have been ripped, you have a dated and signed copy of your work that has a verified record from the post office too.
Its a basic form of protecting yourself. I used to use it all the time when i was a musician (ooh, get *me*)
Hahha!