Update: After the story received plenty of coverage around the Web, and in a fortunate turnaround for German photographer Mirco Wilhelm, Flickr has managed to restore his account. The original story is below.

Mirco Wilhelm, a German photographer, has had a Flickr account for five years, with about 4000 pictures in it, many of them directly linked to from various external websites. When he recently tried to login, he found it odd that he was prompted for his password, and then was asked to create a Flickr account. It turns out that Yahoo had deleted his account by mistake.

The confusion apparently occurred after a different user added Wilhelm as a contact. He quickly realized that the user account only contained obviously stolen material, so he reported it. According to an e-mail Wilhelm received, Flickr staff told him that the account would be checked for irregularities. When he asked if they had mistakenly deleted his account instead of the fraudulent one, it turned that his guess was correct.

Flickr apologized and gave him an additional four years of the Pro subscription for free, but the damage was done. Wilhelm argues that Yahoo should have deactivated his account first, then checked again if everything was in order. In this way, he would have been able to point out the issue and would have not lost any of his hard work. Since the whole account was deleted, the pictures and accompanying links were lost, and Flickr cannot reactivate anything more that the account itself.

"In my day job I actually work as an IT Architect," Wilhelm wrote in a post on his Posterous blog. "I do designs on complex infrastructures, delivery processes and related stuff. Going from an active account to a deleted account is pretty much a NO-GO in any enterprise environment, because of these consequences. If you do something wrong you can't undo it again, without recreating every single setting from scratch. This would be acceptable, if I had a free account. But since I'm a paying customer, I would expect a bit more that a 'Again, I am deeply sorry for this mistake.'"

This is a nightmare story regarding cloud computing. Never, ever rely on a single service. Always create backup. Flickr's apology letter is below:

Hello,

Unfortunately, I have mixed up the accounts and accidentally deleted yours. I am terribly sorry for this grave error and hope that this mistake can be reconciled. Here is what I can do from here:

I can restore your account, although we will not be able to retrieve your photos. I know that there is a lot of history on your account---again, please accept my apology for my negligence. Once I restore your account, I will add four years of free Pro to make up for my error.

Please let me know if there's anything else I can do. Again, I am deeply sorry for this mistake.

Regards,

Flickr staff