Creators of the satirical web site JibJab have decided to go to court to fight for their right to keep running a popular parody of a Woody Guthrie song featuring cartoon images of President Bush and Senator John Kerry. The site had been threatened with a lawsuit by Ludlow Music, which owns the copyright on the Guthrie song, but JibJab decided to strike first, filing a lawsuit of its own in a U.S. District Court. The case could have far-reaching implications for artists’ rights in the digital age.