Officials in New York have charged seven men in what is thought to be the largest international money laundering case ever brought by the United States. The men are employees of Liberty Reserve, a Costa Rica based company, considered the world's biggest online currency exchange.The seven have been accused of laundering money on a massive scale. The company offered online facilities for depositing money and converting it into digital currency which could be transferred to different accounts and withdrawn. Announcing the charges, the Attorney said, the company had become a hub for hackers and traffickers.