Among the various tricks and traps deployed by the NSA is an ingenious little device known as Cottonmouth, built into what appears to be a standard USB cable. It incorporates an RF transceiver, allowing the Agency to receive and implant commands and data via a covert channel. You might want to check your keyboard and mouse - but you'd have to disassemble the USB connector in order to find the transceiver and associated micronics, so unless you're very skilled, you'll just end up trashing your keyboard and rodent.
But hey, no worries; they aren't after you anyway. At least, not that you know of. Of course, they also have a backup plan:
For networks that the NSA can't get to physically, there's NIGHTSTAND, a self-contained Wi-Fi hacking system that can break into networks up to eight miles away, in optimum conditions. NIGHTSTAND hijacks the target network and uses packet injection attacks to install exploits on the target network's computers.
Forget about tax-and-spend, the Agency's gone a little further than that: now they're into tax-and-spy.