Savage was in Canada when he used his US-registered AT&T USB mobile broadband device for a "few hours of surfing". He was later sent a bill that claimed he had transferred 9GB and demanded $11,000. His iPhone was disconnected pending payment.

"AT&T is attempting to charge me 11k for a few hours of web surfing in Canada," said Savage in a Tweet, which was subsequently read by his 63,928 followers.

Savage disputed the bill, claiming that he was told, confusingly, that "data is charged at .015 cents, or a penny and a half, per KB". A later Tweet said he was "about to try to explain the difference to them".

Thanks to his huge following online, the messages were re-broadcast by hundreds of Twitter users, creating a wave of negative publicity for AT&T. The charges have since been overturned.

"Just got off the phone with AT&T and they've taken care of everything to my great satisfaction," said Savage in a later Tweet, before quickly adding an explanation. "AT&T guy on the phone with me: 'apparently you've got enough Twitter followers to get our attention.'"