1. A method comprising: embedding a control mark within an electronic document created by a document word processor, wherein the control mark remains embedded in the electronic document after changing a body of the electronic document with the document word processor; wherein the control mark cannot be changed by or removed with the document word processor; and wherein the control mark includes an encrypted check sum configured to self-authenticate or self-validate the electronic document; detecting at least one packet containing the electronic document transmitted over a network; making a determination that the electronic document has been changed in response to detecting the control mark in the electronic document contained in the at least one packet; and blocking access to the electronic document in response to the determination.
5. The method of claim 1 wherein said detecting at least one packet includes detecting at least one packet transmitted internally within the network.