JitterBugs could turn your keyboard against you:
JitterBug devices are conceptually similar to keystroke loggers, such as the one famously used by the FBI to gather evidence against bookmaker Nicodemo Scarfo Jr. Unlike keystroke loggers, which would have to be physically installed into a subject’s computer and then retrieved, a keyboard JitterBug only needs to be installed. The device itself sends the collected information through any interactive software application where there is a correlation between keyboard activity and network activity, such as instant messaging, SSH or remote desktop applications. The bug leaks the stolen data through short, virtually unnoticeable delays added every time the user presses a key.
Anytime the user surfs the web, sends an e-mail or instant messages someone, an implanted JitterBug could be timed to open a covert jitter channel to send stolen data. According to Shah, a JitterBug could not log and transmit every touch of the key due to limited storage space on the device, but it could be primed to record a keystroke with a particular trigger.