Attorney General Loretta Lynch speaks about a federal crackdown on Medicare fraud. With her are HHS Inspector General Daniel R. Levinson (from left), HHS Secretary Sylvia Mathews Burwell, FBI Director James B. Comey and Assistant Attorney General for the Criminal Division Leslie R. Caldwell. T.J. Kirkpatrick/Getty Images hide caption

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Union soldiers found that gunpowder was sometimes mixed with sawdust. Mathew B. Brady/AP hide caption

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Doctors who bill the federal government for a lot of services may be gaming the system, but there also may be a reasonable explanation. Aslan Alphan/Getty Images hide caption

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A check of Medicare's new database of payments to physicians confirms that at least $6 million in 2012 went to doctors who had been indicted or otherwise sanctioned. iStockphoto hide caption

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