dubdisciple
quantumeffect
I think you guys have this all backwards ... this should be a discussion about the damage to the Black Sabbath brand!
Better groups have been parodied in much more over the top ways with no damage to brand. I doubt this effects the legacy of anyone involved with Sabbath. Hard to damage the rep of a group who's lead singer is known for biting off bat heads and reality tv. Roy Orbison's estate tried to sue @-Live Crew for a raunchy parody of "pretty woman" but it was literally laughed out of court since the jury erupted in laughter when lyrics were read.
Actually, the issue in Campbell v. Acuff-Rose Music (92-1292), 510 U.S. 569 (1994) that was addressed by the Supreme Court was pretty much limited to the holding that the trial court had erred by deciding that the parody issue could be decided primarily on the intent of the infringer to make money, rather than to criticize (one of the statutory fair use exceptions which has been extended to include certain parodies) the original song. That same decision, which is popularly held as being a blanket defense of parody, includes this:
"The fact that parody can claim legitimacy for some appropriation does not, of course, tell either parodist or judge much about where to draw the line. Like a book review quoting the copyrighted material criticized, parody may or may not be fair use, and petitioner's suggestion that any parodic use is presumptively fair has no more justification in law or fact than the equally hopeful claim that any use for news reporting should be presumed fair, see
Harper & Row, 471 U. S., at 561"