From http://www.msnbc.msn.com/id/38843735/ns/world_news-americas/?GT1=43001:

The official said police believe the migrants were mostly from Central America — a population that has been increasingly targeted by drug gangs who demand money from U.S.-bound foreigners or who kidnap them to claim ransoms from relatives in the United States or their home countries.

Oh yeah, and the drug war isn’t working either.

(H/T to Santiago, my husband, for bringing this story to my attention.)