This fascinating article appears on the front page of today's Washington Post:
Some virtual activities clearly violate the law, like trafficking in stolen credit card numbers, he said. Others, like virtual muggings and sex crimes, are harder to define, though they may cause real-life anguish for users....
The question of what is criminal in virtual reality is complicated by disagreements among countries over what is legal even in real life. For example, virtual renderings of child abuse are not a crime in the United States but are considered illegal pornography in some European countries, including Germany.