The mobile phone eavesdropping technology appears similar to that offered by companies like England’s Gamma Group. Rather than conducting a wiretap via a telecom company, such tools allow authorities to lodge Trojan-like spyware on phones to mine data and record conversations.

But it doesn’t end there. Aside from purchasing mobile phone surveillance technology, the Mexican Department of Defense, which confirmed the contracts were genuine, also reportedly splashed out on a kind of radar scanner that allows them to see through walls. These devices have been available to law enforcement agencies for several years, but little is known about where or when they are used. Similar technology was designed by a British company in 2006, and last year researchers at MIT announced that they had developed an “urban war fighter” radar to detect movement through walls from up to 60 feet away.

The Mexican newspapers made scant mention of how the spy technology might be used to track drug lords. El Universal quoted military sources as saying the technology was used by elite members of an intelligence unit for “various tasks, including political espionage”—though the Department of Defense denied this, saying the tools are for legal crime-fighting purposes, keeping Mexico “at the forefront of technological advances.”

Mexican reporters have also been focusing on the shadowy company named in the contracts as the provider of the technology. Security Tracking Devices, which does not appear to have a website, is listed online as being based near Guadalajara in the state of Jalisco. But El Universal tracked the address to a run-down residential area, where it reported it found no evidence of the company’s existence.

The Electronic Frontier Foundation last week criticized the purchase of the technology disclosed in the secret contracts, saying it builds upon a trend of Mexico increasing its surveillance capacity. Mexico has had ongoing help from the United States to install up to 107 monitoring stations for intercepting communications nationwide.

A particular concern is Mexican authorities’ lack of transparency around surveillance, paired with a propensity for corruption. Judicial approval is required for interception of communications in the country. However, to put it lightly, Mexico’s justice system has some problems. Of every 100 crimes in Mexico, only one or two ever reach a judicial ruling because of corruption and incompetence, according to Time. On Tuesday this resulted in an active-duty general and three retired high-ranking army officials being formally charged for their alleged involvement in the drug trade. Human Rights Watch has accused the military, which is spearheading the drug war, of operating with “near total impunity.”

For these reasons, it doesn’t seem far-fetched to suggest that the spy tools could quite easily get into the wrong hands, deployed by corrupt authorities to monitor political opponents or anyone else deemed a threat to drug cartels' grip on power—like journalists. The technology may have been purchased to help fight crime, but it seems almost unavoidable that it will end up being used occasionally to commit crime, too.

**Thanks to Shauna Dillavou for help with Spanish translation.