How do I disable all backup of videos?

I don't want to back up any video content - ever. If it is on my iPad, great, if I lose it I'll back it up from there. However iTunes won't let me do this. In fact, if I turn synch off it DELETES it from my iPad! Very annoying. I'm stuck with either never synching or backing everything up, which actually isn't always possible for me. I just deleted a ton of data just so I could synch. Then I redownloaded it direct on my iPad. This was easier than doing an iTunes backup.

Any ideas to shut off all backups?