for traffickers, it's never been safer to make millions. the men who sell women can hide themselves behind a girl they advertise on the internet. >> we take it very seriously. we've been working with the fbi for years. >> this is a craigslist operation. >> the oakland, california police department trafficking task force has conducted internet sting operations for years. to find exploited girls, they simply follow the internet trail. >> this girl i want to get to. she's 17. >> it's thursday night and oakland pd's human trafficking task force gears up for an undercover sting. >> the undercover officers will be out there in these vehicles in high prostitution areas cruising around. >> tonight oakland's task force will send six new undercovers out on the streets to pose as johns looking to pay cash for sex. >> the mission is to arrest the prostitutes in violation of the law and/or probation.