8. A method of suggesting custodians subject to a litigation hold, comprising: receiving an identification of a first set of custodians subject to a litigation hold; identifying, by one or more processing devices, a set of documents, each document in the set of documents being relevant to the litigation hold and related to one or more custodians in the first set of custodians; determining, by the one or more processing devices, a suggested set of custodians based on a custodian graph between the first set of custodians and a suggested set of custodians that indicates a relationship between the first set of custodians and the suggested set of custodians based on the set of documents, wherein each custodian in the suggested set of custodians is associated with one or more documents in the set of documents and wherein each custodian in the suggested set of custodians is external to the first set of custodians; and providing, by the one or more processing devices, the suggested set of custodians to a user for litigation hold candidacy.
8. A method of suggesting custodians subject to a litigation hold, comprising: receiving an identification of a first set of custodians subject to a litigation hold; identifying, by one or more processing devices, a set of documents, each document in the set of documents being relevant to the litigation hold and related to one or more custodians in the first set of custodians; determining, by the one or more processing devices, a suggested set of custodians based on a custodian graph between the first set of custodians and a suggested set of custodians that indicates a relationship between the first set of custodians and the suggested set of custodians based on the set of documents, wherein each custodian in the suggested set of custodians is associated with one or more documents in the set of documents and wherein each custodian in the suggested set of custodians is external to the first set of custodians; and providing, by the one or more processing devices, the suggested set of custodians to a user for litigation hold candidacy. 12. The method of claim 8 , wherein the custodian graph indicates the relationship based on a keyword shared between at least one of the first set of custodians and at least one of the suggested set of custodians that exists within at least one of the documents.