Pemex estimated that in the first six months of 2012, the volume of oil removed illegally from its national pipeline system through clandestine taps reached 1,841,478 barrels, marking an 18 percent increase from the 1,557,569 barrels stolen during the same period last year.
Several U.S.-based companies operating near the border have been accused of helping Mexican criminals refine stolen oil

According to Milenio, a Pemex official who had received death threats was killed, likely due to "revenge" (28 June 2009).

But what has also percolated just below the surface is an alarming intersection between the drug violence and Mexico’s energy sector. For Mexico and Pemex, the increased intensity of the drug war and its damage is but the latest in a string of challenges, and a twist that has seemingly linked two previously unconnected drags on the nation.
Unofficial figures place thefts from the Pemex network at roughly $2 billion annually. And security experts point to this as an important source of revenue for drug cartels—especially as the Mexican government continues to crack down on them. Thefts from the Pemex network are not new, but the increase and the strain it is placing on the already-taxed company is important. And the illegal tapping has grown significantly in the areas where the drug war is the most pervasive.