Data theft is now a major issue regardless whether in small or large scale organizations. So long as you have important data you can be a victim.
Data theft can be in any form. Since the emerging use of flash drive (a.k.a. thumb drive and flash disk) it has now become the medium to copy the data. Because it is small you can easily hide it in the pocket. Anybody can be a data thief it can be somebody within your organization or somebody who is breaking into your premises.
To prevent data theft you must instigate of blocking the access to USB ports. There are two ways of doing that.
1. You can insert a specially designed lock onto the USB port. This type of lock comes with a key that fits only for that USB port lock. It has another type of lock that holds the USB cable (i.e. keyboard, mouse, printer, scanner, etc.) to prevent the unauthorized people from removing the cable and insert with a flash drive. If you prefer to use this method of sealing the usb ports you have to buy a lock for each port. You will find more information about this on this website http://us.kensington.com/html/17084.html .
2. Install a USB port lock software that will deny an access to the USB ports. Each time a flash drive is inserted it will ask for a password. Just don't forget the password because if you do you might end up formatting your computer to be able to use the USB ports again. If you want to know more about this lock.... http://www.pcworld.com/downloads/file/fid,77358-order,4-c,security/description.html