You've heard of Craigslist and the controversy surrounding the adult services section.
After pressure from law enforcement around the country, Craigslist cracked down on people using its site to traffic young girls. But now it seems like the pimps may have found a new destination to market their product, and it's a website based right here in the valley.
It happens on the streets, in motels, at truck stops. Women selling their bodies for sex.
One hot spot, according to police, is the I-17 and Thomas.
"We see it all the time we see people up and down the street some of these girls are up here hours on end no matter what the temperature is," says Jennifer Trexler, who works nearby.
"Short shorts, low cut shirts, midriffs hanging out, they have very high heels on," says Marsha Johnson.
Some of the women they see are very young. But investigators say they aren't just hitting the streets anymore. Some end up on a website called Backpage.com.
"I just gave the young ladies a ride I have not received any profits," 25-year-old Kendrick Pennington said at his initial court appearance.
Pennington is a prime example. He was charged with child prostitution. According to court papers, the two girls he's accused of selling for sex were just 15 and 17 years old.
Police say their pictures were posted in an ad on Backpage.com.
"He was determined to be the pimp solely responsible for advertising them on the internet," says Phoenix Police Officer James Holmes.
The ads in the adult section are very racy -- explicit pictures and graphic descriptions.
"This is not the first time that that name Backpage has come up, or several other social media sites… no this is not the first time and it is happening frequently."
The site is operated by Village Voice Media, an alternative news weekly chain based right here in Phoenix. It also owns the Phoenix New Times.
There's mounting pressure from several U.S. senators and dozens of mayors across the country to shut the site down. They say it's turning a profit on trafficking children for sex.
But at the same time, some argue this site actually helps police with their investigations -- though police say they don't support a site like this -- they admit it has helped them catch child predators.
"The entire thing is disgusting in the end when you think about sex slaves and children being victimized like this on the internet," says Holmes. "But at the same time it does give us access and I have to admit it does make it easier to follow up and to monitor."
"If I could eliminate trafficking and child sexual exploitation we would do it, we would it in a heartbeat," said Liz McDougall back in 2010, when she testified before congress. "What has happened is the ads have migrated to other sites."
McDougall is the attorney representing Village Voice Media. Back in 2010 she was representing Craigslist in a similar fight over their adult ads, which they eventually shut down.
Over the phone she told FOX 10 her biggest fear is websites like this will eventually be banned in the U.S., forcing them to move overseas -- where the U.S. won't have any control over them.
"Regrettably these children are going to be exploited on the internet. The question is, how much can we stop this and how many can we save if we drive this offshore we are going to unquestionably lose rescues," says McDougall.
She says Backpage.com works with police and has 100 employees monitoring the adult portion of the site for juveniles. She says there's also an automated filtering system that checks for certain key words that may seem suspicious.
But some say whatever they're doing isn't enough, and Backpage.com just makes it easier for child predators to find their prey.
"We have one girl who was on Backpage, she was fully on Backpage, it was very easy for her to get on Backpage," says Lea Benson, president of Streetlight USA, a group fighting back against child prostitution.
"They really should consider what is their obligation to society. It's not just about dollars."
"Is it fair that a business or entity can't operate their business because we think there might be crime or exploitation of minors? It's a difficult question to answer, it's a difficult question for law enforcement to answer," says Holmes.
The state of Washington recently passed a law making it illegal for websites to knowingly publish an escort ad that involves a minor. The hope is that it will force companies to verify the ages of escorts in sex-related posts.
However, Village Voice Media has filed a lawsuit seeking an injunction. Just today, Backpage filed a lawsuit against the state, saying the law is unconstitutional.