Getting college students to attend anything not required is usually a challenge, much less a movie about something as serious and heavy as human trafficking.

But there they were – 350 students in Manhattan College’s Smith Auditorium last Thursday (akin to the start of the weekend on most campuses) — sitting still and silent for the 90-minute film “Call and Response,” which calls attention to the many forms of what is essentially modern-day slavery.

Now, you could say the fact that the film was directed by popular singer-songwriter Justin Dillon, lead singer of the band Cold War Kids — and the fact that Dillon was right there in the room that night — helped with turnout. But that doesn’t explain why practically the entire audience stayed for the whole movie, gave it a standing ovation, and then stayed to ask excellent questions of a panel of experts on this complicated issue. No, the students deserve credit for this and for what many of them are already doing to rapidly turn this issue into a movement.

The film weaves devastating commentary by journalists, actors, performers and other activists about this global criminal enterprise — worth tens of billions of dollars — with stunning performances by pop music stars like Matisyahu and Imogen Heap. Dillon makes a case that music is interwoven with the history of slavery, giving birth to gospel, the blues and other musical forms.

Experts estimate that human trafficking in all its forms —labor slavery, sex slavery, child slavery and child soldiers — ensnares 27 million victims. It’s a horrific crime that is conducted just beyond our view in basements and brothels (even here in the U.S.), in the fields of India and in war-torn Africa where machine gun–toting kids are trained to kill for the regime of the moment. But the film makes you see by taking you to a warren of rooms above San Francisco’s fancy Union Square where immigrant children provide sex to adults, and by showing you that there’s a decent chance the clothes you have on your back are brought to you by slave labor.

After the film, Dillon highlighted some ways every person could help the cause to end human trafficking. In fact, there are 33 ways to help, including going to callandresponse.com to send a message to your favorite retailers that you’re no longer willing to be the final link in their supply chain unless they can guarantee their products are made without slave labor. The site keeps track of how many e-mails people send to each retailer and the responses they get from the companies.

Assemblyman Jeffrey Dinowitz received an award at the film event, for authoring a bill signed into law by Governor Spitzer in 2007 to strengthen and close loopholes in laws to fight human trafficking. At the time, he called it “without a doubt the most important legislation I’ve ever passed.”

There are a lot of crises in the world right now, but however difficult things get for most of us, life will never be as tragic as it is for these fellow human citizens of the world. We can help by educating ourselves, keeping our eyes open and taking action. You can start by going to www.callandresponse.com.