Who owns Youtube videos of personal content (not public mass media content?)

I am aware that the copyright of a Youtube video clip of a professional performer performing belongs to that performer. This question isn’t about that. This question is about all those home movies of cats/toddlers/pickup trucks doing LOLCute! stuff.

Reason I ask is, I know someone who wants to run a contest for prize money wherein folks will submit “My Favorite Youtube Video” from the smorgasbord currently available–IOW not videos that they’ve made themselves, but videos that other people have made and uploaded.

My position is that you can’t do that, because the folks who made the videos own them, and you can’t submit someone else’s work in a contest, because then the person who made the thing would be entitled to the prize money, not you for merely submitting his name.

Just like to have this officially clarified by the collective wisdom of GQ, thanks.

IANAL, but I think that should be ok. Contestants just submit the URL of a youtube clip? There’s no violation of copyright in that case because the clip isn’t being copied.