Making good on their gruesome warning of targeting "internet snitches," members of Mexico's Zetas drug cartel decapitated a woman who was a frequent poster to a website where citizens could post information about drug gang violence.

The victim, Marisol Macias Castaneda, was a newsroom manager for Primera Hora, a newspaper for the border city of Nuevo Laredo. But it was her activity on the site Nuevo Laredo en Vivo, or Nuevo Laredo Live, that seemed to be the source of her murder. The site "prominently features tip hotlines for the Mexican army, navy and police," the AP reports, and "includes a section for reporting the location of drug gang lookouts and drug sales points."

Castaneda used an alias, but the Zetas seemed to have tracked her down. Her body was discovered on a major road, with her head placed on a large stone nearby. Next to her body was a handwritten message that referred to her commenting handle, "La Nena de Laredo," or "Laredo Girl."

"Nuevo Laredo en Vivo and social networking sites, I'm The Laredo Girl, and I'm here because of my reports, and yours," the message read. "For those who don't want to believe, this happened to me because of my actions, for believing in the army and the navy. Thank you for your attention, respectfully, Laredo Girl...ZZZZ."

Now that's terror. [AP, screengrab via Nuevo Laredo en Vivo]