Forget Smashing. Here’s How to Safely Remove Files From a Thumb Drive

How do I get rid of information stored on a portable USB flash or thumb drive? —Donna N.

The short answer, Donna, is to take a hammer and smash the thing to smithereens.

But the very nature of your question suggests that’s not what you want to do. Instead, you want to reformat the drive and reuse it, maybe recycle it or donate it to a family member or friend.

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I suspect that you’re concerned that this small external drive has pictures, videos, files from work and other documents you don’t want nosy neighbors or rivals to see, much less crooks looking to commit fraud or steal your identify.

Your paranoia about stray data is justified

How do you ensure that gone really means gone?

I wouldn’t blame you for feeling a little bit paranoid about deep-sixing data, especially if you never went to the trouble of encrypting or scrambling files in the first place, which would pretty much render the data unreadable to anyone who lacks the password.

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A 2019 study from the University of Hertfordshire in the United Kingdom, commissioned by Comparitech, a consumer website devoted to cybersecurity and privacy, revealed nearly 7 in 10 secondhand flash drives sold in the U.S. and similar numbers in the U.K. contained “recoverable data from their previous owners.”

This may make you wonder where the jump drive with your 2018 tax return is hiding. Hitting Delete on your computer keyboard is not enough to make files vanish, nor is manually attempting to overwrite the drive’s memory.  

“Even if ... it doesn’t look like there is anything valuable there, there may be information that people can access with forensic recovery tools,” says Albert Fox Cahn, executive director of the nonprofit Surveillance Technology Oversight Project in New York.

Reformatting the drive goes a step beyond ‘delete’

If you have uber-sensitive files on the drive, consider data deletion software, some free for home use, that aims to address security vulnerabilities. But for most of us, reformatting the drive to wipe it clean should alleviate most concerns.