1. A method implemented by one or more processors, comprising: identifying a message formulated by a user via a computing device of the user, the message being provided for presentation to: at least a first additional user via a first additional computing device, and a second additional user via a second additional computing device; determining that at least one term included in the message is a vague term; based on the message, formulated by the user, being provided for presentation to the first additional user: identifying user-restricted content associated with the first additional user, wherein the user-restricted content is personal to the first additional user, and wherein access to the user-restricted content is limitable by the first additional user, and using the user-restricted content associated with the first additional user to determine additional information that is related to the vague term, wherein the additional information comprises one or more of: a date, a location, an address, and an identity of an entity; and providing the additional information for presentation with the message, including providing the additional information for presentation to both: the first additional user via the first additional computing device, and the second additional user via the second additional computing device.
6. The method of claim 1 , further comprising: identifying an entity that is associated with the vague term, wherein the determining additional information includes: determining, from the user-restricted content, a second entity that is related to the entity, and determining at least some of the additional information based on the second entity.