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 United States are coming up with different answers and, in the process, showing how an emerging technology can cause rifts in the legal landscape.

The issue emerges just as Kevin Mitnick, the hacker once called by the government "the most-wanted computer criminal in U.S. history," is poised to start using the Internet again. Mitnick served five years for breaking into computer networks of major corporations and stealing software; he was released from prison in January 2000. As a condition of his probation, he has not been allowed to use the Internet -- a restriction that expires today.

Differences of opinion among federal courts are not unusual, although this rift can mean that two people living in different states may receive different sentences, even if they commit similar crimes. A federal appellate court whose opinion interprets law in some Southern states, including Texas, has ruled that people on probation may be barred from using computers and the Internet.

The court argued that although the prohibition could greatly restrict a person's freedom and ability to find work, it also protected society from criminals who have turned the computer into a weapon.

But two other federal appeals courts, including the one governing New York, have recently concluded that such a prohibition is too broad.

The 2nd U.S. Circuit Court of Appeals ruled that the Internet is as vital to everyday existence as the telephone, and that although the government could monitor an offender's computer use, it could not stop it completely.

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