Last October, People for the Ethical Treatment of Animals (PETA) filed suit in federal court alleging that five orcas kept by SeaWorld (three in San Diego and two in Orlando) are being held in slavery in violation of the Thirteenth Amendment to the Constitution. Jeffrey Kerr, PETA's attorney, has said that this is "the next frontier of civil rights." Today Judge Jeffrey Miller heard arguments related to SeaWorld's motion to dismiss the suit.
There's certainly a case to be made that orcas should not be held in captivity, but antislavery law is probably not the best foundation for that case.