Hold your phone in the right light and you'll see all the grimy fingerprint smudges on your beautiful black screen (this is also a great way for someone to steal your passcode). Same goes for your computer — put it to sleep and you'll be able to soak in the streaks of fingerprint trails.
There is now a way to prevent unnecessary touching.
A user on Reddit posted a program that makes your computer shout "Don't touch my screen, bro" whenever someone touches your screen. This is a not-so-gentle reminder to your friends who have a habit of leaving fingerprints behind.
The code is for Linux, meaning if you have an Apple product, you're going to have to jailbreak your device to install the operating system.
See it in action: