If you want to think about moral concepts that ground debates about privacy, you can't help but think about trust. The basis of a community is the trust that the members extend to one another: the trust that we will leave each other in peace, respect one another as human beings, and (hopefully) look out for one another's welfare. Democratic political institutions rely on citizens' trust that fair and open procedures create just societies. Without the possibility of trust, we lose all society, and all social philosophy. Trust is also an important concept in security. We employ security out of a lack of trust. We trust the designers of our security and encryption systems. Citizens encrypt their data or web traffic because they do not trust the government. The government resists citizen use of strong encryption because they do not trust the citizens. It might be easy to conclude that with sufficient trust, we would have no need for security or encryption. I think there are ...