US Patent 11349873 User model-based data loss prevention

A cloud security service provides network security. The cloud security service receives, via a computer network, an electronic message sent by a sending user of an enterprise to a receiving user. The cloud security service analyzes the electronic message using a machine-learned user model describing the sending user's electronic messages, the user model generated based at least in part on previous electronic messages sent by the sending user. The cloud security service determines, based on the analysis, that the electronic message violates a security policy of the enterprise. The cloud security service performs a security action based on the determination that the electronic message violates the security policy.