The girl is 13, maybe 14, an unhappy adolescent with problems at home and a need to get away. Her mother spends most days getting high and is thinking about trading her child's body for drugs. The live-in boyfriend hits on her whenever mom nods out. Last year she dropped out of school.

So she packs a bag and heads for the bus station, because it's the cheapest ticket out of town. As she sits on a bench surrounded by her belongings, a guy appears and starts chatting her up. He seems sympathetic, a good listener. He says nobody should be treated like she's been. He says she deserves better; he says she's pretty. And because she wants desperately for somebody to care about her, she believes him. So when he says why not come with me, I'll make you happy, she says OK.

What she doesn't know is that, in his eyes, she's just prey. In a few days, a week at most, he'll turn her out. Soon she'll be having sex with 10 to 15 men a day. If she balks, she'll be beaten, tortured, disfigured or worse. She's in the equivalent of a hostage situation, alternately brutalized and showered with gifts and affection so that she no longer knows whether to love or fear her captor.

Her pimp will take her from city to city, work her out of hotel rooms, casinos and convention sites, advertise her to customers on the Internet. In her first year she'll earn upwards of $150,000, all of which will go into his pocket.

If she's lucky, she may live to see her 21st birthday.

On any given day in America, according to FBI investigators, some 150,000 underage youths — a large majority of them girls, but some boys too — are forced to work as prostitutes by human traffickers who brutally exploit their youth and vulnerability. Most of these criminals go unpunished. Even when police succeed in making arrests, it's usually the juvenile victims of trafficking rather than the traffickers themselves who end up in jail. The pimps get off scot free.

Over the years, Maryland, an East Coast conduit of human trafficking, has made important progress in going after the criminals who profit from the trade in young lives. Since 2007, child sex trafficking has been a felony punishable by up to 25 years in prison (although trafficking adult women is still only a misdemeanor). This year, the General Assembly approved legislation allowing trafficking victims to have a conviction for prostitution expunged from their records if they can prove they were lured into the trade through force, fraud or coercion. Last year, after authorities in Anne Arundel County rescued a 12-year-old girl who was forced to work as a prostitute at a Laurel hotel, and three other women, including a 16-year-old, from a nearby motel, federal investigators stepped up efforts against traffickers of juveniles.

But the traffickers are resourceful — often moving their victims in and out of the area every few weeks to avoid detection — while the tools available to law enforcement are relatively weak compared to the size of the problem. Since last fall, the Crimes Against Children Squad in the FBI's Baltimore office has rescued 16 juveniles who were forced into prostitution by their pimps. But that's likely only a tiny fraction of the total number of victims, most of whom are never recovered.

Moreover, authorities can't employ many of the tools routinely used against drug traffickers against those who traffic in human lives, such as confiscating their cars and cash. Even a relatively modest proposal to allow trafficking victims to sue pimps for restitution and compensation damages failed to pass the Maryland legislature this year. Another bill permitting victims' rights groups to post a national hotline number for trafficking victims at bus stations, truck stops, highway toll booths and other places trafficking victims might visit was approved only over determined opposition from the state's tourism and hospitality industry.

That's why Maryland lawmakers must continue to push for tougher laws against all forms of human trafficking, which includes not only juveniles forced into prostitution but also many adult sex workers and manual laborers who have been reduced to perpetual involuntary servitude in sweatshops and on farms. Whatever the circumstances that originally brought these unfortunate people into the clutches of their tormentors, no one deserves to be victimized by this modern-day form of slavery.