Those fighting in the war to end human sex trafficking say gangs are getting involved in the activity because women and girls are seen as a renewable commodity.
"With the drugs, you can only sell them once, but with a girl, they can be sold up to 30 times a day," said Juana Zapata with the Chino-based nonprofit group Freeing American Children from Exploitation and Sexual Slavery. "And these girls don't get a day off."
He was one of the more than 50 people who participated in Sunday's Walk Against Human Traffic in Chino Hills.
According to Zapata, there is a misconception that many girls who are victims of trafficking are forcibly taken from their homes.
"Most of the girls aren't kidnapped," she said. "We're working a case where one girl was essentially sold by a family member. Other times they're betrayed by friends."
Attorney General Kamala D. Harris has called human trafficking a low-risk and high-reward crime for gangs.
According to Harris, domestic gangs and Mexican cartels have expanded from trafficking guns and drugs to trafficking humans.
They've become more sophisticated and organized, requiring an equally sophisticated law enforcement response to disrupt and dismantle their networks, she said.
"Police officers, prosecutors, victim advocates and members of the community must work together to change the calculus on human trafficking in California," Harris said in a written statement.
"People think this is something that happens far away or somewhere else," said Laveda Drvol, the organizer and founder of the walk. "People are shocked when they learn it's happening right here in our own backyards."
San Bernardino County District Attorney Michael A. Ramos has helped lead action against trafficking. In 2012, county prosecutors filed 338 prostitution-related cases.
But according to the county Probation Department, exact numbers are hard to come by because young women and girls working as prostitutes are often arrested for crimes that appear to be unrelated.
"Sometimes they're arrested for shoplifting, but when you look at what they're stealing, it's condoms, wet wipes, underwear. All things typically used in prostitution," said Chris Condon, a spokesman for the Probation Department.
The department is working to adopt a sex-trafficking program modeled after one in Dallas. When a girl or boy is arrested or caught for a series of crimes related to human trafficking, an investigator is assigned to the child's case, probation officials said.
On the prosecutorial side, Ramos has announced several directives to strengthen his zero-tolerance policy on human trafficking.
"We have taken significant steps and strengthened existing partnerships to send the message that if you commit this horrendous crime in our county, you will be held accountable to the fullest extent of the law," Ramos said in a recent release.
Ramos said he will attempt to stop human trafficking by going after the customers.
"If we take the customers, or `johns,' and put their photos and names on our webpage once they've been convicted, we're hoping that the shame will stop this troublesome problem over time," Ramos said. "With help from the media, we can generate many avenues of ending this epidemic."
As part of Drvol's crusade to bring awareness to domestic human trafficking, she has pushed to educate young people on the issue and how people can fall prey to the crime.
"Sometimes they're looking for love and they end up looking for it in the wrong places," said Bev Gibbon, the ASB adviser for Western Christian Satellite Program and youth coordinator for Drvol and her campaign.
Technology also has afforded many traffickers an added layer of protection. In the past, many victims and their pimps would've been found standing on street corners, but Internet-based trafficking makes it easier for customers to exchange sex for money, allowing the street-level pimp to be shielded from law enforcement.
Ramos said one of the biggest suppliers of online sex trafficking is the classified-ad website Backpage.com.
Online advertisements for "escorts" can be found for nearly every city in San Bernardino County. Advertisements for young girls and boys could be found selling sexual services - some of whom are as young as 13, he added.
Ramos said the site's adult services ads generate upwards of $22 million a year.
"If Backpage really cares about victims like they say they do, then they should immediately shut down its escort service section," Ramos said. "Clearly, they are more concerned with profit over people."
Calls for comment were not returned by the administrators of the website.
San Bernardino County Coalition Against Sexual Exploitation coordinator Anne-Michelle Ellis said commercial sexual exploitation affects people in all parts of the county.
"It's not just the kids from `those' neighborhoods or `those' families," Ellis said in a written statement. "All children are vulnerable, and the biggest vulnerability is their age."
Zapata said the average age of girls forced into human trafficking is 13.
"The younger they are the more expensive they are," Zapata said.
According to one undercover detective with the San Bernardino Police Department, some of these girls are taken to Las Vegas to work weekends and holidays.
The youngest prostitute she found working the streets of San Bernardino was 13.
But who would pay to have sex with a girl not yet out of junior high school? According to Zapata, it's not who many think.
"It's not the 'pervert' everyone thinks of," Zapata said. "Usually, in our experience, the men are married and have jobs. It's just not what most people think."
Reach Doug via email, call him at 909-386-3925, or find him on Twitter @crimeshutterbug.
Reach Beatriz via email, call her at 909-386-3921, or find her on Twitter @IEBeatriz.