A prominent lesbian activist has filed another federal lawsuit against the 1996 Defense of Marriage Act, which bars federal recognition of same-sex couples. Edith Windsor of New York says she was forced to pay over $350,000 in estate taxes because her marriage to Thea Spyer wasn’t recognized under federal law. Spyer died in 2009. The two married in Canada in 2007 after 41 years as a couple. The suit says the gay marriage ban effectively imposes a new tax on gay and lesbian couples.