The American Civil Liberties Union of Indiana filed a lawsuit Friday morning in U.S. District Court for the Southern District of Indiana on behalf of 15 plaintiffs, including two children of same-sex couples, challenging the same-sex marriage ban and the state's refusal to recognize gay unions legally performed in other states. "The government is a powerful teacher of discrimination," said Sean Lemieux, an attorney working on the ACLU case. "There is no justification for Indiana to treat these families as second-class citizens. The families in this case want the responsibility, security and dignity that only marriage provides, and their children deserve the same protections that other Indiana families enjoy."