The underlying functionality of the Internet at a network engineering level is an esoteric field of study. However, as the Internet becomes more and more central to civic life and international politics it becomes more evident that the structure of the Internet is crucial to cyber-security and privacy.
The Internet has roughly 300 "Internet Exchanges" (IX's) distributed around the world. Internet Exhanges are physical infrastructures through which Internet service providers (ISPs) exchange Internet traffic between their networks.
For historical reasons, Internet Exchanges run "in the clear" without encryption of the data that passes across them. The fact that such volumes of traffic pass without cryptographic assurance of and protection of their contents is a huge security problem, not to mention a privacy implications.
This is why The Calyx Institute is developing a test-bed for an encrypted Internet Exchange, called CRYPTO-IX which will attempt to define a new set of best practices for IX's, by standardizing on security and integrity controls for all data passing from provider to provider.
** UPDATE ** - February, 2014 - We have now secured the commitment of a donation of a number of enterprise-grade ethernet switches to use in our Encrypted Internet Exchange project. Now we simply have to raise enough money to house them in a data center.