An anti-immigration group sued leaders of the Southern Poverty Law Center on Wednesday, claiming their inclusion on the SPLC’s list of hate groups is a racket that violates a RICO law.

In their suit, filed in federal district court in Washington, DC, the Center for Immigration Studies claims their criticism of illegal immigrants does not meet the SPLC’s own definition of a hate group, but they label them so anyway.

The suit also claims that by including them on the hate-group list, the SPLC sought to “‘wreck’ and ‘destroy’ CIS by ruining it financially.”

“SPLC and its leaders have every right to oppose our work on immigration, but they do not have the right to label us a hate group and suggest we are racists,” Mark Krikorian, executive director of CIS, said in a statement announcing the suit.

The suit was filed against Richard Cohen, president of the SPLC, and Heidi Beirich, who publishes the “Hatewatch” blog for the advocacy organization.

“The Center for Immigration Studies richly deserves the hate group label,” Cohen said in a statement. “It has a history of making racially inflammatory statements, associating with white nationalists, and circulating the work of racist writers.”