I was getting very tired of all my applications using up my network bandwidth checking for updates, etc, and this piece of software is exactly what I was looking for.

Not only does it protect against applications using the network, but also it provides a very useful network diagnostic tool with its very useful network monitor (it not only shows what app is using the network, but also where and how it is connecting!).

Plus, the I find the user interface very easy to use, and it gives you full control -- allowing any application to be blocked/enabled for a single user or globally, on any specific port or protocol, and to any host or domain.