Old Phones Spill Secrets. Here's What to Do About It

Today the wires are reeling with a story that sounds familiar at first glance: A guy sold his old cell phone on eBay, and the folks who bought it ended up with his personal information, including text message traffic between him and his mistress.

But here's the spin: The guy who sold the phone followed the manufacturer's instructions to delete all the personal information from the handset. Normally when we hear this story the victim hasn't done anything to delete his personal info, or he's done something rudimentary like just dragging files to the trash. This guy actually tried to protect his privacy and failed.

Admittedly the work it takes to recover deleted data like this is beyond the capabilities of the casual purchaser of used electronics, but the threat is nonetheless very real.

So, what can you do about this? Wipe your info before reselling or recycling your phone. Here's how.

First, remove your SIM card if you have one. This is the first key to protecting your identity if you use a GSM phone (as both Verizon and T-Mobile offer). You'll need it anyway if you plan to upgrade to another phone on the same network.

Next, enter the "clear" command to wipe the memory on the phone. Usually this is a series of button presses or key combinations that will wipe out the internal memory of your phone completely (whether that data is stored on the SIM card or elsewhere in memory). You'll find details on the commands required if you look up your phone on the Cell Phone Data Eraser site. Not every single phone is listed on this site, but a spot check revealed that most models are, and an email address is supplied to request instructions for an additional model.

It's a good idea to run the clear command more than once.

As noted in the original story, the clear command was successful in preventing data recovery on a Palm Treo, but there's ultimately no guarantee that this will irrevocably wipe the data on every phone. Unlike a PC, there's no single utility that can effectively zap a phone the way you can zap a hard drive. It's impossible to know how thorough our poor friend who was having the affair might or might not have been.

If you're extremely paranoid about your data and you think the manufacturer's clear commands may not have done the trick, destroying the phone may be your only choice. If you must smash it, try putting the phone in a sealed Ziploc bag before hitting it a few times with a hammer. This will keep lead and other toxic materials from scattering throughout your garage. You could also consider drilling a few small holes through the handset. Just make sure no matter which method you choose to destroy a cell phone, remove the battery before you start!