Network Tap (not a "Spinal Tap" sequel)
One of the issues I talked about in an earlier article ( http://www.meetdageeks.com/2012/05/is-your-network-firewall-backdoor-open.html ) was about making sure the network infrastructure was secure, That is all the cabling and networking equipment was secure. Look at the following picture and tell me if it is secure. Actually there is a passive network tap inside with a cable going off to a computer in another room. At that other computer someone is eavesdropping or what is known at packet sniffing. The network taps make it easy to record from what you type on the keyboard to recording voip conversations. They require no power and can be made dirt cheap. The only shortcoming is that you have to be nearby to take advantage of it. It would be very easy if someone rented or had access to the office next door to use this device. They might have to punch a hole in the wall to access it unless there is some kind of socket nearby. To record what is coming from the victims compute...