Avast, the company of the famous antivirus, has made an interesting experiment on smartphones with Android system. He bought 20 used ones on Ebay and on these he used the file recovery programs to restore all the deleted data on those phones.
In the end, more than 40, 000 photos were collected, including 1500 of families and children, 750 of women stripped half-naked or naked and 250 photos of the virility of men.
More alarmingly, Avast managed to recover 750 emails and text messages, 1, 000 Google searches, a loan application and more than 250 names and email addresses.
The former owners of these phones, it wasn't that they left that data on display as unwary, only that wiping the data wasn't enough.
As in computers it is possible to recover deleted files, so it can also be done on a smartphone using very simple applications.
We have repeated several times, in our articles, how modern smartphones have nothing less than computers, if not the screen size.
It is therefore normal that all the precautions that must be taken when selling a computer, all the more reason must be taken on a smartphone or tablet.
The reason is simple: deleting a file does not actually remove the file from the device, it simply deletes the reference to find it.
The space occupied by that file is overwritten only when another takes its place (for this reason after a while a file becomes difficult to recover).
In the case of theft, there are some applications to completely erase everything .
Among these, there is the internal function of Android Find My Android, which among the options allows you to remotely delete the memory of your phone.
On the Google store, we can find others to erase the internal memory and that of the SD cards of Android smartphones such as Secure Wipe and Secure Erase iShredder .
Without using applications, moreover, before erasing personal data, you can simply encrypt your Android phone making it encrypted and not recoverable without a PIN or password which is the authorization key
Then remove the memory card (if any), go to Settings > Security > Encrypt your phone (or tablet).
With this function, not only do you protect the contents of the device with a PIN that is requested at power on, but it also protects the contents making it unrecoverable from forensic computer programs (those of data recovery).
The process can take 10 or more minutes and can have the side effect of making the system a bit slower.
Clearing and restoring factory data will completely delete the encrypted data.
On iPhone, the memory is already encrypted so there is no need to do this.
Going to Settings -> General -> Restore -> Clear content and settings you can safely delete all data.
