From the YouTube video description:
More than 200 Thomas Aquinas College students helped lead the way through the streets of San Francisco on January 21, 2012 — in remembrance of the 39th anniversary of Roe v. Wade — for the eighth annual Walk for Life West Coast. The students prayed, sang, and peacefully bore witness to the Culture of Life with some 50,000 walkers.
Roughly two-thirds of Thomas Aquinas students have attended the Walk every year since its founding in 2005, and over the years they have increasingly taken on leadership roles within the event.
By the way, these students are from Thomas Aquinas College in Santa Paula, California, not Aquinas College in Nashville, Tennessee. Both are very good Catholic colleges though, from everything I have heard.
(Found on the Cardinal Newman Society blog via Creative Minority Report.)