SAN FRANCISCO â A Russian man accused of breaking into computer systems at three internet companies in 2012 has been indicted by a federal grand jury in Oakland, Calif.
Yevgeniy Aleksandrovich Nikulin, 29, was arrested this month while vacationing with his girlfriend in the Czech Republic on charges that he hacked into computer networks at LinkedIn, Dropbox and Formspring, damaged computers and conspired to traffic in stolen information.
The arrest of Mr. Nikulin provided a look at the shadowy world of Russian hackers, who appear to operate with relative impunity even as they are accused of escalating attacks on computer networks in the United States. They are accused of attacking a long list of targets, including retailers, banks, energy companies, and more recently, the Democratic National Committee.
Hackers have been able to operate in Russia with little concern about getting arrested, security experts and law enforcement executives say, so long as they do not attack targets inside Russian borders. But they risk arrest when they leave the country.
In 2014, for example, a hacker was arrested in Guam and extradited to the United States for accessing cash register systems at American retailers between 2009 and 2011. A federal jury convicted that hacker, Roman Valerevich Seleznev, of 38 counts of hacking-related charges in August. He is awaiting sentencing.
The grand jury indictment, which was unsealed on Friday, accuses Mr. Nikulin of hacking into the computer networks of the three companies, damaging the computers of LinkedIn and Formspring employees, and using their credentials for further intrusions.
He is also accused of conspiring with unnamed co-conspirators to traffic in user credentials stolen from Formspring, a social networking site. He faces three counts of computer intrusion, two counts of causing damage to a protected computer, two counts of aggravated identity theft, one count of trafficking, and one count of conspiracy.
Mr. Nikulin could face more than 30 years of prison and more than $ 1 million in fines.
The charges were announced on Friday by Brian J. Stretch, a lawyer at the Justice Department, and John F. Bennett, a special agent in charge with the Federal Bureau of Investigation.
Mr. Nikulin, who goes by the online aliases Chinabig01, Dex.007, Valeriy.krutov3 and itBlackHat, was captured in a raid at a hotel in central Prague on Oct. 5. The arrest came 12 hours after authorities there learned he was in the country with his girlfriend and driving a luxury car, according to local police.
He did not resist arrest, but had medical problems and was briefly hospitalized, the police said in a statement. The raid was conducted in collaboration with the F.B.I. after Interpol issued an arrest warrant for him.
Mr. Nikulinâs arrest came two days before the Obama administration formally accused the Russian government of stealing and disclosing emails from the Democratic National Committee and other institutions and prominent individuals.
Federal officials, including Vice President Joseph R. Biden Jr., have said that the United States would respond to the Russian attacks in kind.
After the Czech police arrested Mr. Nikulin, the Russian Embassy in Prague called for his release.
Aleksei Kolmakov, spokesman for the embassy in Prague, was quoted by the state-run Russian news agency Tass as saying, âWe insist that the detained Russian citizen should be transferred to Russia.â
A judge in Prague ordered Mr. Nikulin to remain in custody and a court to examine whether to extradite him to the United States.