With pretty much everyone having a touchscreen phone nowadays that has tons of personal information on it, security is a necessity. But according to new reports at the University of Pennsylvania, common security tools for the iPhone and Android phones aren’t very safe at all. Residual smudges left after either inputting numeral passwords or sliding gestures are the culprit. They can be photographed and, after using simple image software found on most computers, analyzed to find the numbers used in the password. Sure, all of this depends on a thief getting hold of the phone anyway and having a camera, but it is something to be concerned about. In the meantime, wipe your phone’s screen a couple times a day — it can’t hurt.