WASHINGTON, June 28, 2005 -- At any given moment, authorities say, there are an estimated 20,000 sexual predators online, trading child pornography and using chat rooms to lure unsuspecting young teenagers.
FBI agents are online too, posing as teens to snare the pedophiles. But many predators know that FBI agents are patrolling the Web, trying to dupe them.
So three years ago, in an effort to teach FBI agents how to convincingly pass and communicate as a young teen, the agency turned to a new group of experts -- teenage girls.
"You really have a rude awakening in the sense that you have no idea what it's like to be a teenager right now," said Stacey Marie Bradley, a supervising special agent for the FBI's Innocent Images National Initiative, which in the past decade has put more than 4,000 online child pornographers and pedophiles in jail.
An FBI agent involved in tracking pedophiles realized the program was falling short after he took at peak at his teenager daughter's online chats and was confused by the basic chat lingo.
He realized agents had no clue how to accurately communicate as teenagers, so he enlisted the help of his daughter and her friend. Karen and Mary, who preferred to use only their first name for privacy reasons, have since trained 500 undercover FBI agents from around the country.
The high school sophomores test the agents on the latest music, movies, teenage preferences and lingo -- especially online chat abbreviations.
Teen 'Lingo a Different Language'
"They think that the lingo is definitely a different language that they don't understand at all, like 'brb' (be right back)," said Karen.
The tests feature both true and false and multiple choice questions, which the girls update monthly to stay current.
When asked what most teenage girls think about actor Orlando Bloom, for instance, the correct answer would be "A"-- they think he's a "total hottie." And the answer to whether most teenagers love the movie "The Longest Yard" is "true" -- but only the remake, not the original 1974 version.
One agent admitted he was often stumped by the girls' tests.
"I try to keep tabs on some of the more general topics. [On] a lot of the specifics -- music, movies, artists -- I was lost," said Matt, an FBI agent who preferred to use only his first name.
Mary and Karen say they are proud of their role in helping the FBI nab sexual predators. The FBI has secured 2,600 convictions in the time they've been teaching.
"It feels really good 'cause there are so many pedophiles out there," said Mary. "It's like an endless search to help catch them.
But now the FBI is looking for new teenage teachers. Karen and Mary are retiring -- too old for the job at age 16.
Lisa Stark filed this report for "World News Tonight."