Technology can be a bizarre thing. Sometimes, we accidentally delete something and feel crestfallen that we can't get it back. (That is one of the many, many reasons to back that sucker up regularly.) But other times, the things we believe to be gone just refuse to die.

It all depends on how the apps are written, of course. Case in point: With Snapchat, users may think the program obliterates the pics, but it doesn't. The application merely appends ".NOMEDIA" to the end of the files, so they don't appear to the user. End result? They're actually still stashed on the device, ready to be uncovered by hackers or law enforcement officers.

Snapchat images are actually still located on the device, in a folder called RECEIVED_IMAGES_SNAPS. Firms like Decipher Forensics pry into that directory to recover photos for use by lawyers, police or even parents. It's not a fast process — usually it takes about six hours to image all the data on the handset — and not all phones are vulnerable. For now, the company can jack into Android handsets, but it's working on a way to tap the iOS version of Snapchat as well.

Ironically, even though the police might find this scenario useful, they also issue a word of caution. The app is extremely popular, particularly among teens, with many people using it for "sexting." The thought of racy pics that can't be deleted should make people think twice about sexting, or at least using something else other than Snapchat.