It is a truism, these millennia into the haze of civilization, that whenever a person (for whatever reason) finds themselves rummaging through the belongings of a friend or relative - always, of course, with the best of intentions - they will inevitably run across
pornography.
Call it The Law of Maximal Porn Disturbance. There is always porn. The probability of finding porn is, interestingly, inversely proportional to the searcher's expectation of finding porn.
Unless the searchee is a single male. Then the probability is unity.
The malicious giggle of fate doesn't stop there, however. It is also strongly probable that the type of pornography found will force sudden, permanent and in some cases painful changes to the searcher's mental image of the searchee.
Two prescriptions fall out of this kink in the laws of chance. One, avoid rummaging through the belongings (whether physical or virtual, but especially virtual) of your friends, family and acquaintances. Plead blindness. Find sudden important appointments which must, of course, terribly sorry, etc. Explain that your left thumb has been recently infected with a rare form of parasite which, in the presence of clothing (or paper, or keyboards, or whatever is convenient) goes into an involuntary and heroic reproductive cycle, which...
Trail off there. The ellipsis is your friend and ally.
Two, and perhaps more critical, is the strong recommendation to remember that everyone has a kink. Everybody has a special preference than makes them go GLOING (in suitably subdued fashion in public, of course) and most everybody is actually aware that their personal brand of circulatory exciter is something that some people, or most people, or even all people who aren't them, will find horribly disturbing.
Again, unless the searchee is a single male of a particular type. Everyone knows what type this is; there's no point denying it. The type where, as soon as they hand you their keys/laptop/password/car keys you're already cringing inside at the sure and solemn knowledge that your life will be altered - perhaps only slightly, but never well - by what you're inevitably going to find. Those people, those single males of a particular type, are (paradoxically) not the real problem here. Their very nature is such that the searchee will automatically armor themselves in whatever way they are able (metaphorically, or in the case of the ever-handy latex gloves, physically) against the trauma sure to come.
No; the problem is that joker clause involving inverse expectation.
As a result of this law of nature, coupled with a long-time status a 'computer geek du clique,' I have evolved a set of complex protective behaviors which have become entirely automatic over time. Whenever possible, if fixing a computer, I first wipe clean the drive. Whenever de-lousing someone's laptop, I make sure never to click anything with a visual suffix; .jpg, .gif, .avi, .wmv, even such seeming innocents as .pdf - none shall pass. I am he Who Does Not Look.
This has saved me an unknown amount of sanity and therapy bills, not to mention (I am sure) friendships. Friendships destroyed either by the searchee looking into my eyes and shrinking from the horror I have tried so manfully to conceal as I hand back their freshly-restored Macbook, or even (and perhaps worse) by the guileless innocence in their eyes that forever after will serve as blank canvas, in my head, for the myriad of strange and particular sins that I will associate with them.
Fiction (and urban legends) are rife with hushed and fearful tales of technologies that can wipe synapses clean; can suppress or erase memories, can change a person's subjective past or even future. Machines, drugs, psionic talents, toxic sludges, strange and wonderful creatures found beneath the shed, accidents in the space-time continuum, or even quantum. All of these and more have been found in fictive realms to wipe the slate clean. This is done for hire, or for patriotism, or for nefarious gain, or for Men In Black, or for any one of hundreds of reasons. Perhaps one day one of these technologies or accidents or substances will be harnessed, packaged, advertised, purveyed, and made available - and on that day, I swear, I will be first in line holding currency of whatever form. I will proudly slap my purchase down on the counter and think of all the friends I will continue to have past an otherwise painful expiration date; all the pleasant memories of folks and times I will retain, untrammeled by the lurid glow of Fat Chicks, Bald Guys Peeing, Strange Things To Do With Cake, Smothering, Fun With Neoprene, Small Defenseless Creatures Delicately Explored With Tools, Implements of Strange and Unrecognizable Purpose, Interactions Of A Horrific Nature, Wildly Inappropriate Smiling or whatever Capitalized Form of Sin I was tragically unable to avoid seeing and, until the availability of this my mythic balm, would be unable to un-see.