With the advent of social media, everyone should be familiar with the concept of a social network. A social network is a graphical representation of your relationships to other people. A toy example is shown in Figure 1a. In this social network, each node represents a person, say yourself and several friends named A, B, C, D, and E. Each edge signifies a relationship between two people. For example, an edge could signify a friend, a family member, an acquaintance, or a colleague. In general, the nodes could store information such as age, location, and interests. Edges could be encoded with the time that they were created, the type of relationship, or the number of times an interaction has happened.