This week Tim Pawlenty launched his "American Comeback" campaign with an Iowa TV spot featuring the 1980 US Olympic Hockey team. Of course that means ABC's broadcast, which the Pawlenty team didn't get permission from ABC Sports to use (read: they didn't want to pay for it, and it's definitely not a cheap license).
ABC has cried foul and is sending a cease-and-desist letter Pawlenty's way. But as you can see, the commercial is still up on YouTube — a Pawlenty spokesman is citing Fair Use. While the doctrine is often interpreted broadly, it would be interesting to see if a campaign ad qualifies as being in the public interest, rather than as a commercial endeavor.