1. A method to recognize a pseudo message among received messages, the method comprising: receiving messages, including at least one pseudo message, intended for a recipient having an associated recipient Ontology; semantically analyzing content of the received messages and comparing the analyzed content with rules in the recipient Ontology to determine whether the content of any of the received messages is inconsistent with any rules in the recipient Ontology; and upon a determination that any of the compared content of a received message among the received messages is inconsistent with a rule in the recipient Ontology, recognizing the received message as a pseudo message; wherein the content of the pseudo message includes an error sentence that is inconsistent with the rule in the recipient Ontology, and background content into which the error sentence has been inserted; and wherein the background content is configured to obfuscate statistic characteristics of the pseudo message from eavesdroppers.