There's calamity in Cloudland this morning as Gmail fell over rather majorly. Problems started at about 10.30 UK time affecting both individual and corporate Gmail accounts as well as some apps.



Dark clouds over Gmail, which fell over this morning. Photograph: laffy4k/Flickr/Some rights reserved



There's not a peep about the problems on the Official Google Gmail blog, but then that is run from the US. The communications team in London were unable to send out statements on what went wrong... because their email was down.

A spokesman said: "A number of users are having difficulty accessing Gmail and we're working to resolve the problem. We know how important Gmail is to users so we are taking this very seriously and we apologise for any inconvenience caused.

"We encourage anyone having technical difficulties to visit the Gmail help centre at mail.google.com/support."

The Gmail problem was flagged up immediately on Twitter, with many users, though not all, saying they had Imap access running as normal. So anyone being clever and running Gmail through Imap on a desktop email client or through their iPhone app may well be fine.

It is inevitable that this will happen from time to time. What it does prove is that the more data we entrust to the cloud, the more important it is that we have reliable backups in place.

A similar crisis occurred when Amazon Web Services went down almost exactly a year ago; thousands of web-based businesses rely on Amazon for their storage services and after two hours of downtime, users were observing that cloud computing can't become mainstream, certainly for businesses, until it becomes almost infallible.

Within minutes of the Gmail downtime unfolding, I was sent a very pertinent message on Twitter speculating on the cost of the problem:



"Let's count the cost: 25m users, 33% affected; average of $50 per hour lost productivity = $415m per hour economic cost..."

• Update: Two hours later, we're back up. I was asked to do a captcha as my request "looks similar to automated requests from a computer virus of spyware application" - which could well be a clue to the culprit. If someone out there did manage to hack the mighty Google, they will be feeling very chuffed with themselves, regardless of how much disruption they have caused. Now back to work...