Productive Corporation

At a Dave and Buster's restaurant three men gained unauthorized access to the point-of-sale server and installed a packet sniffer designed to capture Track 2 data as it moved from the POS servers to the computer system at the restaurant's headquarters and a data processor's network.  The packet sniffer captured data for approximately 5,000 credit and debit cards which was sold to others who used the information to make fraudulent purchases. 
Productive's Take: There are a few ways in which this could have been prevented. 

1. Host-Based Intrusion Prevention System - this would provide access control to an end-point system as well as notification of abnormalities residing on your network.  CA HIPS can also block USB port access on a particular machine so flash drives or any other unauthorized device cannot connect to the machine.  Check out CA HIPS to learn more about how a host-based intrusion prevention system can proactively secure your environment.
2. Software Hardening - find out which applications are absolutely necessary on the desktop/server and remove all the other applications that are not needed.
3. Hardware Hardening - if you are using a touch screen POS then removing a port for a keyboard should be done.  Also, having a CD drive or any other USB port should be removed if unnecessary for the machine to operate.
4. Encryption - encrypting data and passwords while data is being sent makes packet sniffers useless.  
5. LOCK YOUR SERVER ROOM DOOR 

Read full article here:
http://searchsecurity.techtarget.com/news/article/0,289142,sid14_gci1313708,00.html