MEXICO CITY—She was a crusading Twitter journalist in a bastion of organized crime who chose a photograph of Catwoman as her online avatar and christened herself Felina. Like a comic-book avenger, her alter ego defied the forces of evil in her real-life Gotham of Reynosa, a border city in the Mexican state of Tamaulipas located a short drive from McAllen, Texas. Tamaulipas is notorious as a state caught in the iron grip of organized crime. Extortion, kidnappings, shootouts, arson, bodies excavated from arid pits, all of this happens in Tamaulipas, practically on a daily basis, but hardly any of it gets reported because of a media blackout the cartels decreed four years ago that is as strictly enforced as martial law after a coup.

Two rival drug cartels in Tamaulipas, the Gulf Cartel and the Zetas, have final say over what gets printed or broadcast in the local media. By necessity the people of the state increasingly have turned to social media to share information about organized crime and its infiltration of the government. They are referred to as citizen journalists and have received international attention for their innovative use of sites like Facebook and Twitter to defy the imposition of the blackout.

Felina was an administrator for Valor por Tamaulipas (which means Courage for Tamaulipas), the most popular citizen news hub in the state, with more than 100,000 followers on Twitter and over half a million on Facebook. A sampling of the site’s content varies from the sensational to the specific. There are photos of young teenagers holding military-grade firepower with captions or comments that identify them as members of organized crime. There are posters of missing persons and news alerts about violence that are timely and specific: “At 10am there were isolated gunshots heard coming from Unidad Obrera”; “Since 12:25a.m. Explosions and machine gun fire at Cañada/Fuentes, and pickup trucks passed at high speed on 20th Street”; “In Balcones sector 2 white Ford pickup with 3 armed Men on Everest Street and Seventh.” Soldiers at the Mexican army base in Reynosa also post news alerts to the site about violent confrontations between the army and the narcos.