A report in Milenio describes how the Zetas control the human trafficking trade in the central state of Hidalgo, where an estimated 500,000 migrants (mostly Central American) pass each year. The Zetas have been blamed for last week’s grisly massacre of 72 migrants in Tamaulipas. According to a university study in Hidalgo, the Zetas have had a hand in the human trafficking business since 1997, long before their break with the Gulf Cartel. Migrants who pass through Hidalgo by train or truck must pay extortion fees to the Zetas, or else face beatings or imprisonment. The Zetas’ involvement in human trafficking may be an indication of how it is increasingly difficult to traffic drugs via the U.S. border, forcing cartels to turn to other sources of funding.