U.S. Immigration and Customs Enforcement (ICE) has put up three Bay Area billboards – two in Oakland, one in San Francisco – as part of a 15-city outdoor advertising campaign to call attention to the evils of human trafficking.

The “Hidden in Plain Sight” campaign urges the public to take action if they encounter people who they believe are being sexually exploited or forced to work against their will. Other cities targeted by the campaign are Atlanta, Boston, Dallas, Detroit, Los Angeles, Miami, Philadelphia, Newark, N.J., New Orleans, New York, St. Paul, Minn., San Antonio and Tampa, Fla.

“Most Americans are shocked to learn that in this day and age slavery still exists in this country, including here in the Bay Area,” Mark Wollman, special agent in charge of ICE’s Office of Investigations in San Francisco, said in a news release. “ICE is committed to giving trafficking victims the help they need to come forward so we can put an end to this reprehensible form of modern-day slavery. We are asking the public to help us recognize and identify these victims in our midst – domestic servants, sweat shop employees, sex workers and others lured here by the promise of prosperity, but then forced to work without the ability to leave their situation.”

Just last month, a Walnut Creek woman was convicted on federal charges for having smuggling a Peruvian national into the United States and making her work as a live-in nanny and domestic servant, without pay. Mabelle de la Rosa Dann, 46, faces up to 75 years in federal prison; her sentencing is scheduled for January.

But ICE says identifying victims and their persecutors is tough, as victims often don’t speak English while traffickers often seize victims’ travel and identity documents and threaten their families back home. Although ICE estimates 800,000 men, women and children are trafficked into the sex trade or forced-labor situations around the world each year, ICE launched just 432 human trafficking investigations – 262 involving the sex trade, 170 involving forced labor – in fiscal 2008; in that same year, ICE’s human trafficking investigations led to 189 arrests, 126 indictments and 126 convictions.

That’s under federal law. Here in California, the Penal Code defines someone guilty of human trafficking as “(a)ny person who deprives or violates the personal liberty of another” for purposes of prostitution, child pornography or extortion, “or to obtain forced labor or services” – the victim need not be an immigrant. Oakland’s problems with such trafficking are well-documented, and shocking.

Gov. Arnold Schwarzenegger recently signed into law AB 17 by Assemblyman Sandre Swanson, D-Alameda, which boosts the financial penalties for those convicted of the human trafficking of minors and lets law enforcement seize their assets. Under this new law, half the money collected from such fines and seizures will go to community-based organizations helping underage victims of human trafficking.