In this photo released by Mexico's federal court system, the head of Mexico's powerful teachers' union, Elba Esther Gordillo, stands behind bars as she appears for a hearing at a federal prison in Mexico City, Wednesday, Feb. 27, 2013. Mexico's most powerful woman was formally charged with a massive embezzlement scheme on Wednesday, standing grim-faced behind bars live on national television in what many called a clear message that the new government is asserting its authority.