It is, if we're still debating whether a YouTube clip is "Fair Use". One of the tests of Fair Use being the effect of that use on the material's market. It's

It is, if we're still debating whether a YouTube clip is "Fair Use". One of the tests of Fair Use being the effect of that use on the material's market. It's difficult to argue that YouTube clips kill the value of your product, when your promotions department clearly believes the opposite is true. It might also be of legal relevance, if Viacom were complaining specifically about the clips it uploaded itself and moreso if they tried to use the presence of those clips to pressure a favorable business deal.