O2 is investigating problems with its 3G mobile network in England following 3G outages earlier this week across London and the south of England.
O2's 3G network was out of action in London and across some parts of the south of England for up to 3.5 hours on 17 June.
A number of O2 iPhone customers in the TechRadar office were directly affected by the outage, with the many complaints on Twitter highlighting the scale of the problem.
A spokesperson for O2 said coverage was "patchy" in Hertfordshire, Sussex and London, putting the outage down to planned engineering work which has now been completed.
"Service was restored at 1pm but we continue to monitor the situation closely. We apologise for the inconvenience that this has caused," said an O2 spokesperson.
Phew! For the iPhone addicts at TechRadar that momentary hour of 'disconnect anxiety' was enough to remind us how much we rely on our ubiquitous connections to data networks.