SAN FRANCISCO (KGO) -- An alleged Russian hacker had his day in court in San Francisco after he was extradited overnight.
Yevgeniy Nikulin allegedly targeted three Bay Area companies through cyber-attacks; LinkedIn, Dropbox and Formspring.
The 2012 LinkedIn data breach affected millions. "This is the hack of 114 million LinkedIn users," said Laura Hautala, Staff Reporter for CNET.
In October of 2016, Czech Republic law enforcement officials arrested Nikulin.
CNET's cyber security and privacy reporter says Nikulin allegedly used a LinkedIn employee's username and password to access the usernames and passwords of hundreds of millions more from LinkedIn, Dropbox and Formspring.
"It's really been a waiting game of waiting and seeing is this person actually going to be sent to the United States," said Hautala.
Nikulin was extradited overnight and appeared in federal court Friday morning. The prosecution is the result of a four-year investigation by the FBI, along with Czech Republic authorities and the U.S. Department of Justice.
"It's very rare that a Russian hacker would actually be in the United States facing these charges," said Hautala.
In an emailed statement, a LinkedIn Spokesperson writes, "We've been actively monitoring the FBI's case to pursue those responsible for the 2012 breach of LinkedIn member data. We are glad to see this progress and appreciate the hard work of law enforcement to resolve this investigation."
Experts say the data could have been sold on the dark web.
"What hackers do is take your username and password and compare it to perhaps where you work or your bank or something like that and see if they can get something really valuable," said Hautala.
At the time of the hack, LinkedIn recommended users change their passwords.
Hautala suggests users also create unique passwords for different websites.
Nikulin pleaded not guilty to the charges. He is scheduled to appear in court again next week.
The U.S. Attorney's Office released the following statement: