1. A method comprising: identifying, by a computer system, a policy template that includes information for automated creation of one or more policies for preventing use-restricted content from being sent over a network; identifying, by the computer system, source data having a tabular structure, the source data including a plurality of data elements having the use-restricted content; and automatically creating, by the computer system, a policy and an associated abstract data structure based on the identified policy template and the source data, wherein the abstract data structure does not reveal the plurality of data elements having the use-restricted content, and wherein the policy and the abstract data structure are used for preventing presence of the plurality of data elements in one or more messages sent over the network, the plurality of data elements having the use-restricted content and being from the tabular structure of the identified source data.