Sen. John McCain and the Republican Party have apologized to (and presumably paid) Jackson Browne for their use of his 1977 song "Running on Empty" during the 2008 presidential campaign without obtaining the singer's permission. According to the Guardian:
The apology and pledge [to obtain usage rights to music in the future] were released today along with an announcement of a settlement with Browne over a federal copyright infringement lawsuit filed last year in Los Angeles. Browne sued McCain and the national and Ohio Republican parties for using part of his song Running on Empty to mock Democrat Barack Obama's proposed energy policies in an internet advert....
The musician's suit stated that Browne was concerned that use of his music would cause people to conclude he was endorsing McCain, even though the 60-year-old singer is a self-described liberal.
Chuck Berry, The Foo Fighters, and Van Halen have all been down that brambly path already. If this keeps up, soon the background music at all Republican campaign events will just be a loop of "McCain-Palin Tradition" and "Raisin' McCain." Strongest case for loose IP laws ever.
In the August-September print edition of Reason, Damon Root noted (briefly) Hank Williams, Jr.'s long tradition of political remixes.