Probe after First Lady targeted by mystery website
The Secret Service has joined the investigation into the postings that include documents from people ranging from rapper Jay-Z to the head of the FBI.
The site includes identification numbers, credit reports, addresses and phone numbers.
It bears an internet suffix originally assigned to the Soviet Union and many of the pages feature unflattering pictures or taunting messages of the person featured.
Others whose information is posted include pop star Britney Spears, US attorney general Eric Holder, former Republican candidate for vice president Sarah Palin and Terminator star Arnold Schwarzenegger.
Both the FBI and the Secret Service said they were investigating the site.
White House press secretary Jay Carney said he had “no assessments to offer” on the situation and referred questions to the Secret Service, which would not provide further details.
The site grew from 11 names to 18 in the first 24 hours since it became public, with its operator adding additional features to count the number of visitors and a link to a Twitter account.
It offers no explanation about why the targets were selected or how the information was obtained. The Twitter account includes an anti-police message in Russian.
President Barack Obama told ABC News that he was aware of the investigation.
“We should not be surprised that if we’ve got hackers that want to dig in and have a lot of resources, that they can access this information,” he said.
“Again, not sure how accurate but ... you’ve got websites out there that tell people’s credit card info. That’s how sophisticated they are.”
Online security expert Marc Maiffret said sensitive information can often be gleaned from a single database, but the varied nature of the people targeted made the site’s motives less clear.
Mr Maiffret, chief technology officer for security firm Beyond Trust, said the site contained information that, if accurate, could be very damaging to its targets.