• by Erik Sass , Staff Writer @eriksass1, September 16, 2011

Since the Mexican government declared war on powerful drug cartels in 2006, social media has emerged as one of the main platforms for reporting about drug-related crime and corruption, filling a void left by professional journalists who were intimidated into silence. But for all its supposed advantages, including online anonymity, social media is hardly secure, as was demonstrated by the murder of two online critics earlier this week.

The mangled bodies of a man and a woman, both in their early 20s, were discovered hanging from a bridge Nuevo Laredo, just across the Texas border, along with a banner explaining "This is going to happen to all of those posting funny things on the Internet. You better f*cking pay attention. I'm about to get you." The banner specified two blogs to be avoided, El Blog del Narco and Al Rojo Vivo, both of which have documented murders and official corruption. The note was signed with a "Z," indicating it was left by Los Zetas, a powerful gang based in Tamaulipas province.

The gang apparently wasn't persuaded by El Blog del Narco's claim that it is "not for or against any crime organization," perhaps more concerned by the fact that U.S. counternarcotics officials and drug war analysts regularly consult the blog for information unavailable elsewhere. Meanwhile one contributor at Al Rojo Vivo wasn't impressed: "Don't be afraid to denounce. It's very difficult for them to find out who denounced. They only want to scare society."

Indeed, it's not clear how the gang was able to identify these victims as social media critics. It's possible they simply decided to portray two "ordinary" victims as online opponents, in an attempt to intimidate other critics by way of bluffing. But it's also not hard to imagine informers betraying online critics for cash, and an incautious online tipster might unwittingly give their identity away with just a few contextual clues.

Some of the other popular blogs are Narco Tijuana, Narcotrafico en Mexico and Narcoguerra. While most crimes associated with the Mexican drug war take place in northern states along the U.S. border where smuggling is concentrated, the scope of some the blogs is national, including both official press releases and anonymous tips from federal authorities in Mexico City, and local authorities around the country.  So far the battle between the Mexican government and drug cartels has left about 40,000 people dead, by most independent estimates, including 66 journalists.