Please see the Q&A posted on a recently published page on the Norton site, link provided below:
http://us.norton.com/yoursecurityresource/question.jsp?aid=connection_security
Your Security Resource
Am I creating a security risk when I leave my computer turned on and connected to the Internet 24/7?
In the posted response to this question it was advised to check out a device called DataBreaker; however, from what I could gather it is no longer available unless you are buying it used on eBay.
So my follow on question is, what other hardware devices are there on the market if any that would achieve the same capabilities?