The U.S. Department of Justice has sentenced a Romanian hacker nicknamed "Guccifer" to 52 months in prison, for hacking into the email accounts of about 100 Americans, in a case that exposed the private account used by Hillary Clinton while she was secretary of state. The Justice Department says 44-year-old Marcel Lehel Lazar was sentenced for unauthorized access to a protected computer and aggravated identity theft, committed between 2012 and 2014. Lazar pleaded guilty to the charges in a federal court in Virginia on May 25. Lazar admitted to releasing private emails, photographs, and medical and financial information belonging to his victims. Now-Democratic presidential candidate Hillary Clinton's private email server became the subject of an FBI investigation. The hacker was found to have breached the account of former Clinton political adviser Sidney Blumenthal, where he accessed emails sent to Hillary Clinton. He was also found to have hacked into the account of former Secretary of State Colin Powell and Dorothy Bush Koch, sister of former U.S. President George W. Bush. A separate hacker whose identity is not yet clear, nicknamed "Guccifer 2.0" and also claiming to be Romanian, has been taking credit for data breaches within the Democratic National Committee and the Democratic Congressional Campaign Committee.