The FBI has opened an investigation into a security breach that exposed the contact details of some iPad owners.
A vulnerability in US network operator AT&T's website exposed iPad users' email addresses, before the security flaw was fixed on Tuesday.
"The FBI is aware of these possible computer intrusions and has opened an investigation," FBI spokeswoman Katherine Schweit told the Wall Street Journal, adding that the investigation began on Thursday and was in its early stages.
Apple has apparently refused to comment on the security breach.
Earlier this week a hacker group called Goatse Security claimed it had succeeded in acquiring 114,000 email addresses through the security hole, including those of a number of executives from firms including Dow Jones, Conde Nast, Time Warner, HBO and the US military’s research division, Darpa.