We know mobile phones and devices such as the iPad are vulnerable to being lost or stolen, and that they often don't run anti-virus or other security software that protects full-fledged PCs. But now here's another potential threat to security that comes from those mobile devices: the smudges that your fingers leave on touch screens just might provide clues to the graphical passwords that you entered. In fact, researchers found that the patterns could be discerned about 90 percent of the time, given "ideal lighting conditions."
Of course, if an unauthorized person is able to unlock the phone, he/she might be able to discover all sorts of information, including confidential company info that many users today store on their phones. And if that phone is used to connect back to the corporate network, via a VPN connection or remote desktop connection, for instance, a savvy attacker might be able to do damage remotely using the phone.
With more and more employee-owned devices connecting to company networks, the security of those devices is something IT pros have to worry about.