Von Erck says he and the site's members conceal their real identities because they're afraid of retribution from the people they've targeted. ABCNEWS.com agreed to withhold his real name to protect his privacy.
Because Perverted-Justice volunteers work under condition of anonymity, critics say it's hard to know who to hold responsible when and if a mistake is made.
"There's no way to hold them accountable if they do go over the line," said Scott Morrow, media liaison for Corrupted-Justice.com, an anti-Perverted-Justice organization.
"When you're running an organization or running a group of people with the potential to do as much damage to people's lives as this group does," he said, "I think there also has to be some accountability."
In addition to publishing its targets' names on the Web site, Perverted-Justice publicizes its activity with what it calls "group media busts."
In these "busts," the site teams up with a local television station and lures chatters to a house with what the site's volunteers say is a promise of an underage sexual encounter. When and if the target arrives, he's met by a reporter with a television camera, and soon finds his face on the evening news.
Television stations participating in the stings have come under fire from critics who say the busts tarnish the reputations of people who have been convicted of no crime. They say that because of the nature of the accusations -- even if they are ultimately proved baseless -- the individuals' reputations are often ruined. Critics also say that exposing would-be child molesters is the job of professional law enforcement officers, not a group of amateurs.
But Von Erck dismisses assertions that anyone associated with his site is even capable of making a mistake or perpetrating a fraud.
"We have layers of redundancy and technology that allow us to not make those mistakes," he said.
At least one recently publicized case suggests Perverted-Justice is not always accurate.
Earlier this year The Associated Press reported that a Milwaukee bank teller was shocked when she received a threatening phone call from a man who said her number was posted on Perverted-Justice.com as belonging to a suspected child predator. The woman said she had never been online or even owned a computer, and was forced to change her telephone number.
Von Erck says the number had previously belonged to the individual the site was targeting but that when he moved it was reissued to the unsuspecting teller. He said the site had since changed its policy to ensure the same thing did not happen again, and now automatically removes telephone numbers that have been posted for more than two months.
Von Erck says he and a friend started the site in July 2002 after witnessing what he called "sickening" behavior in chat rooms for residents of Portland, Ore., where he lives.
"I was chatting in the Portland rooms for about two years," he said. When someone appearing to be a minor would enter the chat room, Von Erck said, adult men would immediately approach that chatter. "It was like throwing blood in the water around a bunch of sharks," he said.
A self-proclaimed libertarian and professional wrestling aficionado, Von Erck runs several Web sites where he talks about his hobbies and interests. One of the sites says he is planning to make a bid for the U.S. presidency in 2016.