If a person goes to prison for using a computer and the Internet to commit a crime, can he be barred from using computers or the Internet after the sentence is served?

Courts are increasingly facing the question as the Internet age gives rise to an explosion of cybercrime. But appellate courts in different parts of the country are coming up with different answers and, in the process, showing how an emerging technology can cause rifts in the legal landscape.

A federal appellate court whose opinion interprets law in some southern states, including Texas, has ruled that people on probation can be barred from using computers and the Internet. The court argued that while this prohibition can greatly restrict a person's freedom and ability to find work, it also protects society from criminals who have turned the computer into a weapon.

But two other federal appeals courts have recently concluded that such a prohibition is too broad. In overturning the sentence of a child pornographer last year, the Second U.S. Circuit Court of Appeals ruled that the Internet is as vital to everyday existence as the telephone, and that while the government could monitor an offender's computer use, it could not stop it completely.

And the Third U.S. Circuit Court of Appeals, whose jurisdiction covers New Jersey and Pennsylvania, has issued conflicting opinions. In one case in 2000, it allowed a complete ban to stand, but in another -- issued recently -- it argued that such a condition was overly broad. In this case, involving a man convicted of possessing child pornography, the court said these sentences would have to depend on the facts in each individual case.

The courts have noted that computers now pervade virtually every area of life, suggesting a reason they have found a complete ban excessive, said Jennifer Granick, director of the Stanford Center for Internet and Society.

"Computers are everywhere," she said. "The ATM is a computer; the car has a computer; the Palm Pilot is a computer. Without a computer in this day and age, you can't work, you can't communicate, you can't function as people normally do in modern society."

Monitoring technologies

The impact has been felt, too, by probation officers, whose jobs are to monitor offenders' activities after they are released from prison. Where they cannot rely on a complete Internet ban, probation officers are being forced to pioneer new ways to make sure that offenders on probation or on supervised pre-trial release do not use computers and the Internet to commit new crimes.

That has meant finding technologies to monitor what Web sites offenders visit and what e-mail messages they send.

"This made our jobs more difficult," Brian Kelly, a federal probation officer in New York, said of the decision last spring in the case of Gregory Sofsky by the Second U.S. Circuit Court of Appeals, which includes New York, Connecticut and Vermont. Initially, Sofsky, who was convicted of receiving child pornography on his home computer, was sentenced to 10 years in prison, after which he would not be allowed to use the Internet for three years.

His successful appeal means not only that he will be allowed to use the Internet after his release from prison, but that sentences prohibiting Internet use are invalid for other offenders, too. The ruling has resulted in modified sentences for at least seven other people in the region, who originally were prevented from using computers while on supervised release -- a term that can refer to probation or someone's pretrial release.

Under the modified sentences, they still cannot use computers or the Internet at will. They are restricted in what Web sites they can visit, what chat rooms they can attend, and what people they can associate with online.

In the Eastern District of New York, the job of monitoring has fallen to Kelly and several colleagues, who employ technologies that let them observe an offender's computer activity remotely. For instance, they have installed software on several offenders' computers that lets them dial into an offender's computer and get a log of his Web surfing and other online activities.

"I see every e-mail, every chat, every instant message," Kelly said recently.

Kelly is planning to add biometric fingerprinting equipment, which scans a person's fingerprint before allowing access to a computer. Kelly said the technology would help him know exactly who was logged on to a computer, and thus prevent an offender from asserting that an illegal activity, such as downloading child pornography, took place when someone else was using the computer.

The monitoring technology is still far from foolproof, Kelly said, noting that a sophisticated computer user probably can find ways to evade it.

Evading detection
But even the high-technology monitoring methods leave much to be desired, said Scott Charney, chief security strategist for Microsoft and a former federal prosecutor who headed the computer crime and intellectual property section for the Justice Department. They "can be easily circumvented," he said, noting, for example, that a child pornographer could find ways to use the computer to obtain, then eliminate, offending images before being caught.

Still, Charney added that from a legal standpoint, there is a very good reason to sentence people to limited Internet access "even if the technology is not there to enforce it." He said the sentence was an important deterrent because an offender knows that if he is caught, he will go back to prison without getting another trial.