Although the use of computers by government to detect fraud now is readily accepted, how they are used is triggering widespread debate. The main issue is privacy. Government officials defend the compilation of personal data by computers as a boon to keeping crime in check.
They say millions, perhaps billions, of taxpayers' dollars are saved annually by computers that turn up cheaters on welfare, food stamps, and workmen's compensation; locating fleeing fathers who fail to make child-support payments; rounding up those who ignore traffic tickets; and determining who may be underpaying state and federal taxes.
On the other hand, civil rights activists say that using computers for these purposes can lead to abuse of individual liberties, sometimes undermining constitutional rights - including that of assuming innocence until guilt is proved.
So-called computer ''matching'' (comparing various government electronic files on individuals) vs. the rights of the individual has been a subject of controversy at the American Bar Association's meetings here.
Lawyers and government officials generally agree that computer excesses and error could lead to a miscarriage of justice. But the two sides differ over what the remedies should be.
Thomas McBride, associate dean of Stanford Law School, asserts that the right of privacy is not specifically spelled out in the US Constitution. Dean McBride has served as Inspector General for the US Department of Labor. He was in charge of computer matching to detect fraud.
McBride insists that federal coffers are protected and the public well served by matching, which includes such things as comparing welfare-recipient rolls to salary or income records. He says one such computer ''hit'' in the Southeastern part of the United States turned up $500 million in unpaid federal taxes.
The Stanford dean also points out that computers are pinpointing social security fraud, in which people who have passed away remain on the rolls, while others forge the signature of the deceased on monthly checks.
However, McBride admits that major problems still exist in gathering and verifying data. He would have Congress broaden the provisions of federal privacy statutes to limit computer access and possible abuse of individual rights.
John Shattuck, national legal director of the American Civil Liberties Union (ACLU), insists that computer affronts to constitutional guarantees are more real than imagined.
He points to examples when government agencies, overzealous to catch cheaters , prematurely publicized their ''hits'' before adequately verifying the data.
For instance, when welfare rolls in Massachusetts were matched against bank-deposit information, fraud was immediately assumed. However, in some cases it later was proved that the data were incorrect or there were logical and lawful reasons for the savings.
Mr. Shattuck also scores what he sees as frivolous computer matching - such as recent comparison in Hawaii of a list of food-stamp recipients with a ledger of yacht owners. Various public opinion polls indicate that 74 percent of Americans feel that government is increasingly looking over their shoulders, and 91 percent lay the blame on unregulated flow of private information into government data systems, says the ACLU's legal director.
Shattuck concedes that some computer matching is justified. But he insists that there must be stronger safeguards against excesses and heavy penalties for those who misuse electronic systems. He points to instances during the 1960s when Internal Revenue Service data were being used to punish activists and dissenters in America.
Shattuck and other lawyers here say premature publicity about fraud as a result of computer detection also raises serious questions about ''due process'' guarantees. Fourth Amendment rights to trial and defense may be circumvented when recipients are prematurely terminated from welfare rolls before fraud is adequately proved, they explain.
''The real culprit is not the computer itself,'' insists attorney Ron Plesser. ''It's the people who use them.'' Mr. Plesser served as general counsel for the Federal Privacy Protection Study Commission, which grew out of the Federal Privacy Act of 1974. The FPPSC studied the relationship between the data gathered and the individuals involved.
Plesser says legal recourse is limited for individuals harmed by incorrect or misused computer data. As recently interpreted by the courts, such relief usually extends only to out-of-pocket losses or, in some cases, is allowed only when there is physical injury, he points out.
Plesser advocates independent oversight of privacy questions. He points out that the Office of Management and Budget, which now oversees this function, cannot be impartial because its primary interest is eliminating fraud.
Other suggestions here include:
* Creation of a permanent privacy commission to study and report use and abuse of computers by government agencies. (The FPPSC's congressional mandate has run out.)
* Strict limits on computer matches.
* Greater efforts to detect welfare fraud ''up front'' - disqualifying welfare applicants when they apply.
* Stiff penalties for agencies that misuse the system.