As I have about 500 videos on our course I use embedding from a third party video hosting company Hugh. Sample course using this approach (not finished!!) http://tinyurl.com/zy32war
It is true that nothing is impossible, but making it harder is a good goal. Even embedding can make the video rippable with various tools (mostoy progressive HTTP video streaming. If you host with a third party video CDN and opt for RTSP streaming then that is much much harder to do, but more expensive due to the technology behind it.
If you'd like to discuss further - I would be happy to share my experiences, feel free to DM, if you're all sorted then no worries