CHRIS HANSEN Profile -- is a correspondent for NBC News’ award-winning newsmagazine "Dateline NBC," who reported in an unprecedented hidden camera investigation of sexual predators on the Internet.  Predators scouring the Internet, targeting children for sex: It's a national problem that Chris Hansen with Dateline has helped uncover. We got such an overwhelming response from our last investigation— some 15,000 emails from parents, grandparents, teachers and law enforcement— telling us to "keep up the good work," and "keep the issue alive." On Wednesday night, April 26, Dateline is back with the fourth undercover investigation. This time, we traveled to small town America. Even far from the big cities and suburbs, vulnerable young teens are not far from danger. A warning: some of what you're about to read is explicit.

Two years ago, Dateline launched an undercover investigation into on-line sexual predators.

We had no idea we were about to expose a national epidemic: adults trolling the Internet looking to meet young teens for sex.

Our investigations revealed the enormity of the problem. Over the course of three undercover stings, we exposed almost 90 men. 

Our past investigations have been in major metropolitan areas: the first near New York City, the second in a suburb of Washington D.C., and the third close to Los Angeles.

Could it be that this is a crime that only happens in and around big cities, or does it happen everywhere? Even in rural America?

This report is Dateline’s fourth investigation into Internet predators—only this time, we went straight to the heartland: Greenville, Ohio, population 13,000.

Nestled among the corn fields and cow pastures, Dateline found a large house just the right size for our crew and specialty cameras. It was outside of Dayton Ohio, and six hours from Chicago.

"Frag" and "Del," their screen names, are from Perverted-Justice.com, an online watch dog group that for the last four years has been catching Internet sex predators and exposing them.  We hired the organization as consultants so we could watch them do what they normally do— go into chat rooms and pose as 12-to-15-year-olds home alone interested in having sex. 

So while the Perverted-Justice decoys troll chat rooms, our crews set up 11 hidden cameras—seven outside covering all angles of the driveway, side, and back of the house and four cameras on the inside.

One man emerges from the shadows. He’s 40-year-old Alonzo Wade. He’s been chatting online about sex with a girl who said she was 15. When she says she’s worried she’ll get pregnant he says “I am fixed.”

He drives 104 miles, more than two hours, to meet the young teen home along. And he’s loaded down with alcohol. Del, pretending to be the young girl waves him in.

If you have a story or need a speaker, email Chris Dateline@NBC.com