1. A method of annotating an unindexed document, comprising: receiving, by a computing device from a portable capture device, a first digital image depicting at least a first portion of the unindexed document, wherein the unindexed document is unknown to an index of stored documents; receiving, by the computing device, an annotation associated with the unindexed document from a first user of the portable capture device; extracting, by the computing device, features from the first digital image; storing, by the computing device, the first digital image, the extracted features, and the annotation as an annotated digital image; recognizing, by the computing device, a second user from the features of the first digital image, wherein the first digital image depicts at least the first portion of the unindexed document and the unindexed document is associated with the annotation from the first user; responsive to recognizing the second user from the features of the first digital image depicting at least the first portion of the unindexed document, creating a new tie between the first user and the second user in a network of users who have captured documents with similar features; and responsive to creating the new tie, making the annotated digital image available to the second user and sharing an identity of the second user with the first user; determining a first group of users, including the first user, who have operated on the unindexed document from users who have ties with the second user in the network; determining a second group of users who have not operated on the unindexed document from the users who have ties with the second user in the network; and weakening, by the computing device, the ties between the second user and the second group of users of the network based on the first group being larger than the second group.