Mobile phone users on O2 have been hit by connectivity and service problems since the weekend.
O2 used Twitter to inform users of the problems.
"We're sorry that some mobile customers have had problems with data today - these services will be back up tonight," the O2 Twitter feed said on Sunday evening.
On Monday, an update followed: "We apologise to customers who cannot use data at the moment. We have a fault with the allocation of IP addresses which we are fixing".
O2 was not alone in using Twitter to highlight the problems. "My iPhone is refusing to connect with the cellular data network despite a healthy 3G interface. Any ideas?" Shaun Of The Dead star Simon Pegg tweeted.
"Seems to fixed. Am able to tweet and go again. How quickly we learn to rely on things we don't understand," Pegg later reported while marvelling the festive snow in London's Crouch End.
In a statement O2 told Sky News Online yesterday: "We are aware of an issue currently impacting data access for some of our customers", having identified the fault with the allocation of IP addresses.
Two O2 updates followed on Monday via Twitter. "Quick data services update: the system fault has been fixed and internet connections are gradually being restored," and "MMS and Visual Voicemail remain affected - we're working on these as a priority."
More updates are being added on Tuesday morning, O2 denying in a tweet that some responses had been sarcastic. "No sarcasm, just offering alternatives if there are problems."
O2 customers have suffered problems with lack of internet and email earlier this year, in July and August for instance, when the company apologised for a poor and patchy service.
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See also: O2 brings 4G LTE network to the UK