User-generated advertising, "uncharted legal waters"

Everyone likes, YouTube (well, not Viacom), but is user generated content really a good advertising strategy? Consumer-Created Ads Cause Grief for Companies

Money quotes:

"The idea of doing that is fraught with all sorts of risks that aren't worth the business benefit," said Douglas Wood, a New York-based attorney who is a co-chairman for the advertising, technology and media law group at Reed Smith. "If clients listen, they won't do it."
....
"You need to step back and say: What negative impact could this have on my brand?"