DOMA challenged today in Massachusetts federal court:

Gay & Lesbian Advocates & Defenders (GLAD) has filed a challenge to the federal definition of marriage codified in Section 3 of the Defense of Marriage Act, which prevents the federal government from treating gay couples married under state law as married under federal law. (GLAD is the group that brought the successful challenge to Massachusetts' marriage law.)

The 92-page Complaint is available here. It claims that the plaintiffs, married under state law, were denied federal benefits that would have been available to them if they were opposite-sex married couples. The underlying constitutional claim is that Section 3 violates the equal protection principles applicable to the federal government through the Fifth Amendment. The group has more about the suit here.

(Thanks to Chris Geidner for the pointer.)