That phone you so generously turned over to another may be harboring some of your secrets

— and it may be all too willing to spill its guts. An examination of 20 used phones purchased on eBay turned up more than 1,500 family photos of kids, 750 photos of women in various stages of undress, and more than 250 selfies of men’s nether regions, according to Avast. The identities of four previous owners of the devices, one completed loan application, more than 250 contact names and email addresses, more than 750 emails and text messages, and more than 1,000 Google searches also were recovered.

To wipe the data off smartphones does not work, and the data can be recovered Avast Security has warned. The company recovered tons of data, including more than 40,000 stored photographs, from 20 used Android phones purchased from eBay.

Device owners need to overwrite their files to make them irretrievable, and this is because RAM-based memory still uses the same file system as hard drives, and PC files do not really get deleted either, which is why then can be recovered when deleted accidentally.

Good news for iPhone owners however, because although Avast did not analyze iPhones in general on iOS, recovery is much more complicated which depends on the version of iOS, the version of the device, and whether files on the device are encrypted.

Both Android and iOS are based on Unix-like operating systems, and both use use flash storage so it’s highly likely that data on both can be retrieved after it has been deleted. Tablets are just as vulnerable to data retrieval and there are an increasing number of data recovery tools aimed at the Android and iOS operating systems, which can be used by unscrupulous dealers to get to your data.

So what can you do to protect your privacy? Well encrypting your data is a good option, whilst ensuring that the data is overwritten (not just deleted) will go some way to help. Or simply not not resell or give away your old phones if want to be sure!