1. A method for performing data loss prevention, comprising: creating for a user, using a data processing system, respective permissive policies with a most permissive enforcement action for each content category of a resource, wherein the content category includes at least two categories; forming, using the data processing system, a policy set based on the respective permissive policies; creating, using the data processing system, an effective policy from the policy set using a least permissive enforcement action; and applying, using the data processing system, the effective policy to determine whether a user action is permitted on the resource.