The Romanian hacker who allegedly stole and posted information on former presidents, diplomats and federal officials, as well as celebrities, and is credited for outing Hillary Clinton's use of a personal email server while serving as secretary of state, made his first appearance in an American court on April 1.

Marcel Lehel Lazăr, a.k.a. "Guccifer," 44, was extradited to the U.S. in March and stood before a federal judge last week to face charges of wire fraud (three counts), gaining unauthorized access to protected computers (three counts), aggravated identity theft, cyberstalking and obstruction of justice.

From December 2012 through January 2014, Lazăr allegedly hacked into the private email accounts of former general and diplomat Colin Powell, a member of the Bush family — releasing private photos of former President George H.W. Bush and self-portraits painted by former President George W. Bush — and former Secretary of State Clinton, among others.

The Clinton emails were the first evidence that the official-turned-presidential-candidate violated federal regulations by using a private email server, an issue that continues to dog her campaign as the FBI investigates the seriousness of this breach of protocol.

Along with the theft and release of personal information, Lazăr is accused of impersonating one of his victims in 2013, leading to the identity theft charge.

"Marcel Lazăr is the latest of a dozen high-level cybercriminals who have recently been extradited to face justice in the United States," Assistant Attorney General Leslie Caldwell said after Lazăr appeared in court. "Old-fashioned investigative work, enhanced international law enforcement relationships and a long memory can ensure that foreign-based hackers have no safe haven even in the remote corners of the globe. As the saying goes, 'They can run, but they can't hide.'"

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According to the indictment and statements by Lazăr, he used social engineering to gain access to user accounts, rather than malware or advanced hacking tools. At the time of his arrest in January 2014 by Romanian authorities, Lazăr identified himself as an unemployed taxi driver.

Lazăr told The Smoking Gun — the news outlet to which he first released the Clinton emails — that he did not fight the extradition request. His trip to the U.S. comes in the middle of serving a seven-year sentence handed down by Romanian authorities.