....Scavenging

Scavenging, sometimes called browsing, is a method of obtaining information
that may be left in or around a computer system after the execution of a job.
Simple physical scavenging could be the searching of trash barrels for copies 
of discarded computer listings or carbon paper from multiple-part forms.  
More technical and sophisticated methods of scavenging involve searching for
residual data left in a computer after a job is completed.

For example, a computer operating system may not properly erase buffer storage
areas used for the temporary storage of input or output data.  Some operating
systems do not erase magnetic disk or magnetic tape storage media because of 
the excessive computer time required to do this.  Therefore, new data are
written over the old data.  It may be possible to read the old data before
they are replaced by new data.

"Fighting Computer Crime" by Parker, Donn B. (C) 1983 by Donn B. Parker
Charles Scribner's Sons, New York.  pp. 76-77.
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Donn P. Parker is Senior Management Systems Consultant and reasearcher 
computer crime and security at SRI International in Menlo Park, California,
for clients worldwide.  The author of "Crime by Computer" and two 
professional books on computer security, he gives about fifty lectures
a year on computer crime and security.

