1. A method for determining network connectivity between a first node and a second node connected to the first node by at least one path, the method comprising: automatically obtaining user interaction information between entities of an online network community from a plurality of sources, wherein the sources are chosen from a group consisting of social media networks, political party memberships, religious organization memberships, ratings agencies, credit bureaus, consumer complaints, criminal histories, legal records, media, search engine results, official document issuers, email services, data syndicators, address databases, transportation passenger lists, gambling databases, business listings, hospital affiliations, and university affiliations; determining user connectivity values indicative of trustworthiness based on the user interaction information; receiving, from a user device, a request for a network connectivity value indicative of a trustworthiness associated with a second entity of the online network community, wherein a first node represents a first entity in a social network graph and a second node represents the second entity in the social network graph; in response to the request, determining the network connectivity value, wherein determining the network connectivity value comprises: retrieving, from a first memory, a first list that identifies outgoing paths from the first node of the social network graph; retrieving, from a second memory, a second list that identifies incoming paths to the second node of the social network graph; joining an incoming path to the second node with an outgoing path from the first node to produce a joined path, wherein joining comprises: selecting the outgoing path from the first node from the first list; and searching the second list for the incoming path to the second node that corresponds to the outgoing path from the first node; extracting, from the first and the second lists, user connectivity values associated with links of the joined path; and multiplying the user connectivity values associated with the links of the joined path with a minimum user connectivity value assigned to a link in the joined path; and communicating an indication of the network connectivity value to the user device, wherein the user device is configured to automatically make at least one network-based decision regarding the second entity based on a magnitude of the network connectivity value.