A hacker group known as AntiSec claims it stole the identification numbers for 12 million Apple devices and has posted information on a million of them on a website.
AntiSec, which is short for anti-security, alleges it gained access to a file containing the list of the Apple IDs after hacking into the computer of an FBI agent. It did not identify the agent or who the ID numbers belonged to.
AntiSec said it chose to release a portion of the Apple IDs list to get people's attention to its claims that the FBI is gathering people's Apple device details.
"Well we have learnt [sic] it seems quite clear nobody pays attention if you just come and say 'hey, FBI is using your device detail,' " the group said in a note posted online.
The group claims that some of the devices on the list also contain names, telephone numbers, addresses and ZIP codes. However, AntiSec said it chose to reveal only user IDs, device types and device names in the portion of the list it released.
You can check if your Apple device ID, which is known as a Unique Device Identifier or UDID, was among the 1 million released with a tool created by The Next Web. For now, though, it isn't clear what real damage anyone can do with your device's ID or how to protect yourself if it was stolen or released.
The FBI told the Los Angeles Times it was aware of the alleged hack but a spokeswoman said the agency could not comment further.
Apple could not be immediately reached for comment.