Shortly after they confiscated the suspect's computers for forensic examination, he fled.

When the detectives finally caught up with Walter Savage more than a year later, he was holed up in a room he had rented in a house in Yeadon - and he was back on a computer chasing his cyberspace fantasies.

But this time, Savage was using his neighbor's unprotected wireless signal. On his new computer, he had downloaded more than 100 images of child and adult pornography.

For law enforcement, tapping into wireless accounts is the latest way in which child pornography can evade the reach of the law.

"I think we are going to find more and more of it," said Delaware County Detective David Pfeifer, who is with the Internet Crimes Against Children (ICAC) task force.

Computer users, he said, do not often take the extra step to secure their wireless Internet routers, leaving their accounts vulnerable to Internet theft from outside the home.

Delaware County District Attorney G. Michael Green said there were more cases where child pornography was being downloaded by criminals using wireless service registered to another person. "That technique is a real concern," he said.

And it can also become a real problem for the unsuspecting wireless owner. The person who downloaded the pornography is gone, and it is the registered owner of the wireless account who is left to answer police questions.

Technically, "the account holder is responsible for the crime," said Detective Sgt. Gordon Samartino of the New Jersey State Police ICAC in Hamilton, where there have been a few cases involving the use of unprotected wireless to access child pornography.

"The search warrant ends up at that house," he said.

In apartment complexes or streets where houses are close together, it is easy for neighbors or drive-by cyberspace pilferers to pick up and use WiFi signals from unsecured wireless routers without paying for access.

"We view it the same as if you split into someone's cable line," said Mitch Bowling, a senior vice president at Comcast. "It is theft of services."

Bowling admits it is hard to find the offenders. Often, he said, "they are nomadic."