Apple, of Cupertino, Calif., had no immediate comment.
AntiSec claimed it had hacked as many as 12 million records of Apple customers and their personal information, for buyers of iPhones, iPads and iPod Touch devices. It only published a million of them.
The hacker group claimed it had obtained data from a laptop used by an agent of the FBI. An online statement said it was probing into alleged abuses of privacy by the FBI.
The FBI declined comment. It also didn't publish anything about AntiSec on its website.
Standing for "Anti-Security Movement," AntiSec claims it was conceived in 1999 as countermeasure against "the cyber-security industry and their tendency to disclose security vulnerabilities as a scare tactic to drive sales profit in computer security programs."
To be sure, that was the same year as computer programmers worldwide took precautions against the so-called Y2k bug that was feared to cause electronic havoc in Jan. 1, 2000, when computer systems had to roll over into the new century. Billions were spent on the effort and the event passed without consequence.
Apple shares rose $9.03 to $674.27 in late Tuesday trading.