The data was downloaded by a hacking group known as Goatse Security, which obtained the information after stumbling upon a program on AT&T's website that would send back the iPad user's email address when given a unique SIM card identification number known as an ICC-ID (Integrated Circuit Card Identifier).
By guessing ICC-ID numbers, the hackers were able to download 114,000 email addresses, according to the website Gawker, which first reported the news.
"AT&T was informed by a business customer on Monday of the potential exposure of their iPad ICC-IDs," AT&T spokesman Mark Siegel.
"This issue was escalated to the highest levels of the company and was corrected by Tuesday; and we have essentially turned off the feature that provided the email addresses."
AT&T said the only information hackers could have obtained as a result of this bug was the email address attached to the iPad. That data could have been misused by spammers.
AT&T plans to inform customers whose email addresses were obtained, Siegel said.
"At this point, there is no evidence that any other customer information was shared."
There are some pretty powerful iPad users out there, apparently.
After examining the hackers' data, Gawker found email addresses belonging to White House Chief of Staff Rahm Emanuel, New York Mayor Michael Bloomberg and ABC News Anchor Diane Sawyer, as well as addresses belonging to Google, Amazon, Microsoft and the US military.
"The person or group who discovered this gap did not contact AT&T," Siegel said.
Neither Apple nor Goatse Security responded to requests for comment.