Neither small to large enterprises nor government institutions are immune to the threats that pervade today’s security landscape. Leakage of congressional documents, a half million credit card numbers hacked from a leading web host provider, and even a major security vendor falling victim to a website breach are just a few recent headlines that proclaim the costly network threats facing organizations of all types and sizes.

These network threats can typically be classified into four categories: threats coming in, threats invited in, threats already in, and threats going out. Incoming threats typically deal with network perimeter attacks, such as SQL and XSS injections that...