By Fatos Bytyci PRISTINA (Reuters) - A Kosovo man arrested in Malaysia on charges of hacking the personal information of U.S. security officers and passing it to Islamic State was well known to Kosovo police before he left to study abroad. The U.S. justice Department said Ardit Ferizi, 20, had been charged with hacking the details of 1,351 U.S. military personnel and federal employees and handing them over to the militant group in Syria so it could target the individuals. He was arrested in Malaysia on Friday, and will be extradited to the United States, authorities in Kuala Lumpur said. A Kosovo police official who spoke on condition of anonymity said Ferizi had been arrested and released in Kosovo before he left to study abroad. He had been questioned on charges of hacking internet sites in Kosovo. "Police had a lot of information on what he did, when he left Kosovo," he told Reuters. In 2009, Ferizi claimed responsibility for hacking Kosovo's biggest news portal Gazeta Express. He was critical of the portal's reporting on radical Islamists and Islamic State in Syria and Iraq, where 100-200 Kosovars are known to have gone to fight. Some 40 have died so far in the conflict. Berat Buzhala, the CEO of Gazeta Express, told Reuters he had been in touch with Ferizi between 2010 and 2014 via Facebook and phone. CAMERAS HACKED "Many times he sent me security camera photos from Kosovo institutions. From border crossings. He had all Kosovo security cameras under his control. Also from the airport. He had access in real time," Buzhala said. "I told everything to the anti-terrorist police unit." Buzhala said he had even informed U.S. embassy officials in Kosovo, asking them if they could press local police to stop attacks on his news portal. "I alerted the U.S. embassy and gave them his (Ferizi's) name," he said. Buzhala said Kosovo police had been "totally indifferent" to his complaints over Ferizi. The young hacker left his hometown Gjakova last year to study computer science and forensics at a private institute in Kuala Lumpur. Ferizi's father told Kosovo news portal Kallxo he was "shocked" to learn his son had been arrested. "We are a traditional educated Albanian family, we are pro-American," he was quoted as saying. Ethnic Albanians, most of whom are Muslim but secular, make up more than 90 percent of Kosovo's 2 million population. The country considers itself a staunch ally of the United States, which led the NATO bombing of Serbia in 1999 that paved the way for Kosovo's formal secession from Serbia in 2008. Earlier this year, Kosovo adopted a law introducing jail sentences of up to 15 years for anyone found guilty of fighting in wars abroad. (Reporting by Fatos Bytyci; Editing by Ivana Sekularac and Andrew Roche)