I was asked by a musical institution to do online guitar videos back when I had instructional videos up on you-tube. It sounded very interesting, and they even paid if people took the courses you uploaded. I started to look into it, and in the contract they stated that they would own the rights to the video. No big deal, I was doing it for them. However after that they stated (in quite a bit of legal mumbo jumbo) that they would then own ANY video you uploaded to several different sites (youtube, muvio etc).
When I pointed this out, they said "oh that's not true, anything you create outside of us is yours". However when asked to pull it from the contract before signing, they refused. I'm still doing videos, they aren't even around anymore.