Recent studies show that deleting photos, documents, and other files in smartphones, by doing a factory setting reset, might not be enough to permanently remove data.

For as long as handheld phones had the "reset factory settings" option, consumers always assumed this feature reverts phones into their base settings, leaving no trace of the user's original data nor any of the changes they have made on the phone. Essentially, factory reset was supposed to send the phone back in time, so the next user can enjoy original features and settings, even from a pre-owned phone.

Like Us on Facebook

Unfortunately, reports made by the University of Cambridge's computer researches revealed that a certain amount of the data stored by the previous owner still remains within the phone, even after a factory reset. Many claims purport that hackers smart enough could easily gain access to these data. This leaves all secondhand phones (there are more than 630 million worldwide) vulnerable to privacy attacks.

The researchers studied more than 21 smartphones, many of which were made by Google, Motorola, HTC, LG, and Samsung. In every instance, the researchers were able to access more than 80 percent of the data previously erased through factory settings. In a disturbing note, this includes private messages, emails, photos, and even security data for social networking sites.

A different study by Avast security software company released a slew of data recovery tools on more than 20 different secondhand phones, purchased through eBay. According to Mashable, Avast found more than 40,000 photos, which included family photos, selfies, and some rather incriminating and sexually-oriented photos.

While researchers in both Cambridge and Avast studies admitted that there were slight variations in the security problems of these phones, one thing remained true all throughout the studies: factory reset does not make for permanent deletion. It is said that there are many disk-management software and apps out there but they typically take much longer to delete data on a device, because these programs offer more efficient security wipes than a conventional hard reset.

Evidently, one of the problems with the factory reset are the modern data storage systems that store redundant copies of stored data. While redundancy is an excellent feature for storage and accessibility, it poses problems when it comes to securely wiping out a phone's contents.

Tagsfactory settings, Data Reset