Imagine going to the bank to retrieve important documents from your safe-deposit box and finding nothing there. By that, I mean nothing - the bank itself has disappeared, leaving an empty building and no forwarding address.
Would you be just a trifle concerned?
That's what happened in March to thousands of customers who stored their digital images on a Web site called ClubPhoto.com. It was the latest among the scores of photo sharing Web sites that popped up during the dot-com boom but then went belly-up.
Their owners discovered, the hard way, that attracting customers and making money were two different propositions.
I know about this because I was one of ClubPhoto's longtime customers. Over five years, I'd created dozens of online albums that chronicled family gatherings, vacations, wrestling matches, football games, proms, birthdays, graduations and other happy events.
Friends and relatives browsed the photos online, and I used ClubPhoto's printing service to send copies to the unwired. The print quality was better than I could produce at home, the prices were reasonable, and it took a lot less time than printing myself.
My particular chapter of this story appears to have a happy ending, or at least one that avoids total disaster. That's because another online photo outfit called Winkflash.com bought the defunct ClubPhoto's servers at auction and is gradually restoring its customers' albums - mine among them.
For that, I'm grateful. Although I had the originals of those digital images, they're scattered all over my hard drives, and they would have taken weeks to reorganize.
And the incident taught me a lesson: No matter how attractive and convenient online file storage may seem, you're never really safe unless you have backup on a disk or hard drive you can put your hands on.
It took me a couple of months to figure out exactly what happened to ClubPhoto. All I knew at the outset was that one day in March, when I tried to log in to upload new photos, my browser gave me a 404 Error.
That's geek-speak for "Not found." It usually turns up when a Web server has crashed or when you mistakenly enter the name of a nonexistent Web page in your browser's address bar.
Most 404 problems are resolved within a few hours, when the server goes back online. But ClubPhoto never returned, and we never got as much as an e-mail from the company that operated the site.
One reason I had trusted ClubPhoto was that it wasn't free. It allowed customers to keep albums online for up to 90 days at no charge, but I paid $25 a year, which allowed me to maintain up to 30 permanent albums.
I figured an outfit with a steady rental income would be more likely to stay afloat than a business that depended strictly on low-margin print orders.
But from Web research, news archives and conversations with some of those involved, I learned that the ClubPhoto service to which I originally subscribed - and liked so much - was bought by an outfit called Photo TLC of Petaluma, Calif.
Until that time, Photo TLC was basically in the fulfillment business, which means it produced the photo mugs, mouse pads, albums, custom prints and T-shirts that customers ordered from other online photo sites.
Although it had millions in venture funding, including a big poke from Disney's Steamboat Ventures, employees said Photo TLC squandered its opportunities, and on March 6, it sent its employees home without warning or explanation. A few days later, the ClubPhoto site disappeared, also without warning.
(This was actually the second photo site that was shot out from under me. In the early days of photo sharing, I signed up with one of the pioneers, Zing.com. I was crushed when the company shut down its retail operation in 2001. To its credit, Zing did give us notice and a process to return photos to those who wanted them.)
Back to the current case. Enter Winkflash, a Rhode Island-based photo sharing site that has managed to survive the shakeout and saw an opportunity to salvage ClubPhoto's customers.
Darrell Lucente, Winkflash's vice president for marketing, told me the company bought ClubPhoto's servers, which contained something like 40 terabytes of information (that's 40 trillion bytes).
Winkflash set up a site on the old ClubPhoto home page, urging customers to register with Winkflash to have their photos transferred. But no one knew exactly how ClubPhoto had stored its data; Lucente said it was devilishly difficult to figure out how to retrieve all those photos.
As weeks and then months rolled by without any sign of my old albums, I was ready to give up.
A few weeks ago, on a whim, I decided to give Winkflash one last try, and sure enough, there were all my old ClubPhoto albums. Thanks, guys! You have my business.
Now for the sermon. I was merely inconvenienced when ClubPhoto.com disappeared. But some other customers, for reasons unfathomable, kept their only copies of their photos online, or had their only copies scattered piecemeal around the house.
Most online photo sites will put your albums on a CD for a relatively small fee (Anything less than $50 is a pittance if you figure out how long it would take you to restore a well-organized online collection from original images.)
So take advantage of the offer. The only constant in the online world is that what is here today can literally be gone tomorrow.