Next story: Experts see link between child pornography and sexual abuse cases.

"Thomas" knew he was somewhere he didn't belong.

The lewd images of young boys — pictures that had once sent him scrambling to turn off his computer — now enslaved him for hours every day.

Thomas was addicted to child pornography.

Three years after downloading his first pornographic image of adolescent males, Thomas, who asked his real name not be used, is serving two life sentences at the Utah State Prison for sexually abusing his own 6-year-old son.

His story is told here not because it is so different but rather all too common.

Officials say child pornography was almost eradicated in the early 1980s. The U.S. Postal Service, working closely with law enforcement, caught child pornographers when they attempted to ship their goods.

Enter the Internet — and a new era in the exploitation of children, nationally and right here in Utah.

In 1995, the state of Utah filed six charges of sexual exploitation of a minor, the state statute under which the possession of child pornography is prosecuted.

Last year, 158 charges were filed.

Despite this alarming growth, officials say many people don't understand what child pornography is, how it's prosecuted, and what can be done to stop it.

"We close the door and the blinds because it's not a nice thing to talk about," said Lt. Ken Hansen, head of the Utah Internet Crimes Against Children Task Force. "But we're overwhelmed with our child pornography cases. It's all over the place."

Thomas started looking at adult pornography on his computer in 1995. Three years later he stumbled onto some child pornography in a news group, a type of computer message board where people post and download news, pictures and sometimes pornography. News groups were around before the Internet and allowed large volumes of text and image files to be traded among users.

"At first I got out of it because I knew that this stuff stays with your computer and I stayed away from it for awhile," Thomas said. "There were lots of times I'd hear a noise outside and I'd have to look outside and see if the police were at my door. . . . Then I waited a few weeks. The cops didn't show up. . . . After a long time of seeing I wasn't getting caught —the police weren't showing up at my door — I would binge for hours and hours."