Companies caught up in the YouTube craze are eager to put videos created by consumers on their Web sites and in TV spots — but their attorneys are trying to restrain them long enough to explain the legal pitfalls of such advertising.

The consumer clips are typically rounded up through a contest, with a promise to broadcast or post the winners. In a recent Doritos campaign, the winners were aired in commercials during last month’s Super Bowl XLI football game and are still posted online.