If you're recycling a computer or a hard drive, don't just assume that deleting files will wipe the data off your system, because it won't. All it does is reformat the space on the drive, and the data can be snagged using tools designed for disaster recovery.
You need to get a disk-wiping program, preferably one that meets the U.S. Department of Defense's Media Sanitation Guidelines, and you need to set aside a few hours. What a good disk-wiping program will do is write all sorts of data on your hard disk multiple times, effectively obscuring your original data with newer, nonpersonal stuff. This takes some time, so don't procrastinate and leave it to the morning of your planned recycling run.
Mac users looking for disk-wiping programs can use Apple's built-in Disk Utility, or they can cough up $25 for Mireth Technology's ShredIt X. Windows users on a budget can erase their drives using the free Eraser 6.0.10.
If you're tempted to skip this step, consider this: In 2003, graduate students at MIT bought 158 used hard drives--approximately 60 percent of them reformatted and 45 percent with no files on them at all--and they were able to pull more 5000 credit card numbers, personal and corporate financial records, and medical records from these "wiped" drives. While the odds of a graduate student at an elite technical university pulling your personal data off that old MacBook and using it for evildoing are low, why not make them even lower? (Some people recommend physically drilling holes in hard-drive platters, but even that may not be enough.)
If you're recycling a digital camera and its attendant memory card, you'll need to wipe the card too. The best way to do this is to stick any memory card back in the camera and use the camera's built-in "format card" option to wipe the memory card clean of all data.
If you're getting rid of memory sticks, USB flash drives, and other small storage drives, reformat the drive, preferably with a disk-writing program. Remember, throwing out files doesn't delete the data.
If you're getting rid of old printers, scanners, or fax machines, you'll need to purge the appliance's memory. The good news is, most consumer-grade printers, scanners, and fax machines don't have internal hard drives. (Most of the time, the document you're printing or scanning is stored in RAM in the appliance's hardware.) All you have to do is disconnect your appliance from any computer, and then turn it on and go through the settings until you find the option to reset everything to factory settings. That should flush out any residual data or personal information like your fax number.
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