Comment Sometimes I hear a story that is simply breathtaking in its stupidity and potential for disaster. For your delectation, horror, and amazement, here is one relayed to me by a good friend a few days ago.

He's living in a European country that shall remain unnamed; in addition, the names and some details have been changed to protect the guilty (and the very dumb). It was transmitted to me via Skype, so I've also cleaned up the spelling and punctuation common to IM conversations so that it's more readable.

Boy have I got a story for your SecurityFocus column. My brother-in-law just bought a used Intel 20" iMac. The seller was a nice looking blonde, who didn't wipe the disk. You can probably see where this is going, but it's better than that.

For some reason, he thought he needed her password to reinstall the system, so he called her and she gave it to him. Well, he had already seen some pornographic pictures on the hard drive that weren't password protected. Most of them weren't too explicit, aside from a couple of [oral sex] shots. But the password uncovered some videos where she gets sodomized, apparently by her boyfriend, or only one guy at any rate.

Now the pics and vids are all on his iPod. He pulled them off the computer.

It gets better.

At this point, I was thinking, "How in the world could it?" But my buddy was right. It got better.

My brother-in-law doesn't watch a lot of television, but somehow he figured out that the blonde is the host of [a very popular television show in that country]! I saw the vids and I went to the official website, and there she was. There's no doubt about it, it's the same woman.

I couldn't believe it either. How can you be that stupid!?

Don't even bother asking me for her name, or the name of the TV show, as I've been sworn to secrecy. Instead, let's ponder the lessons we can learn from this salacious debacle.

Lesson 1: Wipe your disks

I've touched on this one before, and I know it seems like common sense to the folks reading this column, but my pal's story sure makes one thing painfully clear: many (most?) "ordinary" users don't understand the concepts of wiping a hard drive securely before relinquishing a computer.

It's one thing to drag your personal files to the trash and then empty it - lots of people undoubtedly think that will be enough to protect them. A few more knowledgeable ones understand that trashed files can still be recovered, so they want to remove that sensitive data more completely.

This usually means asking a friendly computer nerd for advice or help, or Googling for freeware, or paying for some commercial piece of software that will overwrite data the necessary number of times (Editor's note: Mac users can use the Secure Empty Trash menu to securely delete files). A tiny number of people - call them "paranoid security experts" - will go the final step and drill, bash, or bend their hard drives so that the data will be totally unrecoverable.

And then we have the...well, I don't really want to call them users, since they're more used by than users of their computers - people who don't even try to remove their data from the PCs in their possession. Even if that data is intensely personal. As in, involving acts or knowledge that really should be kept private.

Or, to put it another way, in what reality did that young woman think leaving pictures of her engaged in sexual acts on her Mac was a good idea? Did she not understand that those images and videos were left on the machine that she was selling? Had she copied them somewhere - to another machine, an iPod, or a USB stick - and thought that copying was actually moving?

The embarrassing goodies didn't have to be sexy pics and vids, of course. They could just as easily have been IM conversations, or emails, or letters, or banking info, or accounts of medical issues, or just about anything that should be seen as privy to only a very few. No matter what it is, the lesson is crystal clear: destroy that data before it leaves your possession!

Lesson 2: Protect your passwords

But now we come to the second incomprehensible action our randy young lass committed. Once again, I've written before about the cavalier attitude many computer users display toward their passwords. This one, however, is just shocking in its utter imbecility. Selling your computer, I can understand. Accidentally leaving naughty JPEGs and MPEGs behind I don't comprehend, but I can kind of - maybe, just barely, if I'm really feeling charitable and "in the giving vein," as Richard III says - understand someone making a horrible mistake and thinking that stuff is gone when it's really still there. But giving away your password when the buyer calls? No questions asked? What the...? Do you see my face right now? Jaw dropped, eyes wide open in total disbelief, mouth agape? LADY, HAS BEING ON TV COMPLETELY MELTED YOUR [expletive] BRAIN?

Let's review, shall we? One, wipe your computer clean before you hand it off to a new owner. Two, if the new owner calls you requesting your password, don't give it to him. There is no three.

Once the toothpaste leaves the tube...

So, my TV personality friend, you've decided to whip out the digicam and take some shots of yourself and a male companion. But stills weren't enough, so you added movies to the mix. Spicy! Unfortunately, once something has been committed to a digital file, it can be copied and transferred around the world in an instant.

Seinfeld's Kramer,Michael Richards, has certainly learned that lesson over the last week or so. Claire Swire and Peter Chung found out the hard way when their emails zoomed from inbox to inbox. Same thing for homophobic landscapers, rude managers in New Zealand, and incompetent HP support personnel: all had their stories sweep around the world, to their detriment.

Eventually, music and movie BigCo's will learn this painfully obvious truism, whether or not they really wish to, and DRM, in all its useless, inefficient, and consumer-hating glory, will go bye-bye.

With this understanding, let's talk like reasonable adults here, Ms European TV Personality. Here's the deal: unless you have an exhibitionist streak a kilometre wide (I used that instead of "mile" since you use the metric system), you really, really, really shouldn't take photos and movies of yourself in flagrante delicto. It doesn't matter how much in love (or lust) you think you are with the dude.

Murphy's Law holds here about as strongly as anywhere else, so I can guaran-freakin'-tee you that those very embarrassing items will end up in the possession of people you'd rather were not possessing them. Whether through accident, theft, anger, maliciousness, or lasciviousness, someone besides you and your lover is going to get their paws on those jpegs and movies, and at that point, potentially anyone who can access the internet is going to get quite an eyeful. Girl gone wild, indeed.

Look at my friend's brother-in-law. What's the first thing he did after discovering the goods and showing them to my buddy? Why, put them on his iPod, of course! All the better to show other friends. And to transfer...or upload...or add to YouTube...or...you get the idea. So far he's resisting urges to spread the movies and images around, but how much longer will he resist?

Do you really want to find out, oh lady of mystery? On the one hand, it's unfortunate that this entire incident has happened to you, since at any moment you could find yourself needing to do a lot of red-faced explaining; on the other, though, it's almost too bad that I won't publish your name and identity.

Perhaps if that info was made public, it would cause you and a lot of other people to learn a very painful, and very real in today's world, lesson about security, privacy, and the importance of keeping personal matters secret.

This article originally appeared in Security Focus.

Copyright © 2006, SecurityFocus

Scott Granneman teaches at Washington University in St Louis, consults for WebSanity, and writes for SecurityFocus and Linux Magazine. His latest book, Hacking Knoppix, is in stores now.