1. A method of securing data in a computer network against a plurality of computer events with an electronic attack monitor generating a corresponding plurality of attack warnings, said data, sought to be secured, having one or more security sensitive words, characters, icons or data objects, said computer network having, interconnected together, a plurality of computers for a plurality of users having a corresponding a plurality of security levels each with a respective security clearance, one of said plurality of computers designated as a data input computer and each of said plurality of computers having a memory therein, a first and a second memory designated as a remainder store and an extract store in one or more computers of said plurality of computers, comprising: filtering data input from said data input computer dependent upon respective ones of said plurality of attack warnings and extracting said security sensitive words, characters, icons or data objects from said data to obtain extracted data and remainder data, the degree of extraction dependent upon respective ones of said plurality of attack warnings; storing said extracted data and said remainder data in said extract store and said remainder store based upon respective ones of said plurality of attack warnings; and, permitting reconstruction of some or all of said data via said extracted data and remainder data only in the presence of a predetermined security clearance of said plurality of security levels.