YouTube has changed their Terms and Conditions to say “we own your content”.
“…by submitting the User Submissions to YouTube, you hereby grant YouTube a worldwide, non-exclusive, royalty-free, sublicenseable and transferable license to use, reproduce, distribute, prepare derivative works of, display, and perform the User Submissions in connection with the YouTube Website and YouTube’s (and its successor’s) business… in any media formats and through any media channels.”
Essentially they could use your content and sell it to advertisers for use without ever paying you a dime. Got a hot song that you made a video for? They could strip out the audio and sell it on a CD.
Watch out for yourselves before you upload that content.