EncryptKeeper writes: Ars Technica has a in-depth (an disturbing) feature on deep packet inspection. ISPs are starting to turn to deep packet inspection to monitor their network, and more troubling, look at how they can use it to shape, block, monitor, and prioritize traffic. 'The "deep" in deep packet inspection refers to the fact that these boxes don't simply look at the header information as packets pass through them. Rather, they move beyond the IP and TCP header information to look at the payload of the packet. The goal is to identify the applications being used on the network, but some of these devices can go much further; those from a company like Narus, for instance, can look inside all traffic from a specific IP address, pick out the HTTP traffic, then drill even further down to capture only traffic headed to and from Gmail, and can even reassemble emails as they are typed out by the user.'