In 1890, a Census Bureau employee invented punch cards so population data could be tabulated electronically. The rest is history. Robert Ellis Smith, publisher of the monthly Privacy Journal, has pulled together enough material on all the organizations collecting and exchanging data on us--banks, credit companies, employers, schools, etc.--to make paranoids of the most level-headed. Much is familiar--the myth of private medical records, the overuse of Social Security numbers--but there are new ideas too (prospective jurors often fill out detailed questionnaires and answer personal questions in court, all of which becomes part of their ""files""), and each section ends with ""What You Can Do"" to protect your privacy in a particular area. The right to privacy is not specifically guaranteed in the Constitution, Smith notes, although it is implied in certain amendments, and courts have begun recognizing it. But protection is still largely up to the individual. ""Nowadays, when people talk about privacy,"" says Smith, they really mean ""the right to know what facts about them are being kept and used by others and the right to keep that information accurate and fair."" Smith illustrates privacy violations with case histories--the man unable to expunge an ancient shoplifting charge; the mother removing irrelevant data from her son's school file. A guide for the bedeviled, then, not another exposâ€š, and consequently, all the more valuable.