Before seeking a declaratory judgment that "This Land" does not infringe Guthrie's original copyrighted work, Jib Jab responded less formally to Ludlow Music. In a letter, Jib Jab noted, "It is enough that the parody here is readily and objectively perceptible, as demonstrated by the fact that a variety of commentators already perceive it clearly."

http://www.eff.org/IP//20040728_Ltr_to_LiCalsi.pdf

To support its point, the parodist cited the following tech news website and blog:

http://www.corante.com/importance/archives/005314.php
http://www.blawgchannel.com/2004/07/copyright_my_tw.html

Unfortunately, Jib Jab's litigation counsel (EFF) omitted the citations from its complaint in the U.S. District Court for the Northern District of California. Maybe they will reappear in future briefs.