Although technological security measures are widely used, they are invariably defeated. As a consequence, document protection is ultimately derived from legal safeguards. However, proving malfeasance in a court of law is not as straightforward as you might think. Whereas computer forensics allows data to be retrieved from digital storage media and presented in court, it is singularly incapable of proving who stored or created the data in the first place. As many defence lawyers, judges and juries are unaware of the esoteric ins and outs of computer science, the potential for miscarriages of justice is considerable. An overview of the problems. Michael Caloyannides (PhD) is adjunct professor of Computer Science at two universities in the Washington D.C. area, and advises NASA on its deep space exploration program. He was awarded the prestigious Scientist of the Year award in 1987. In addition to numerous technical papers, Michael has published two books on the subject of computer forensics and privacy (`Computer Forensics and Privacy`, Artech House 2001, and `Desktop Witness`, John Wiley, 2002). He is a regular columnist and associate editor of `security and Privacy`, a magazine published by the IEEE Computer Society.