María del Rosario Fuentes Rubio, best known under the pseudonym “Felina”, was kidnapped by armed men on 15 October in the Mexican state of Tamaulipas. The following day a photograph of her body was posted to her Twitter account with messages warning others to be silent.

A doctor by profession, Fuentes Rubio was a contributor to the Valor por Tamaulipas citizen information service, a website that seeks to expose violence and organised crime activities in the state. She posted under the handle @Miut3, which has since been suspended by Twitter. Fuentes Rubio actively posted alerts that pinpointed the location of violent incidents in real time. Her online activities defied the media blackout imposed by drug cartels since 2010.

“The work of individuals like Fuentes Rubio is critical in an environment where the press is muzzled by organised crime groups. Her murder is yet another blow to the right to information and to freedom of expression, and highlights the risks faced by individuals in the country who are striving to expose wrongdoings,” said Index on Censorship Chief Executive Jodie Ginsberg. “Impunity for the killing of journalists and digital activists is a threat to media and online freedom. We urge the authorities to investigate the killing thoroughly to identify and bring to justice those responsible.”

This is not the first time organised crime groups have targeted journalists and citizens who use the internet to provide information on violence and criminal activities. According to Reporters Without Borders, “four netizens were murdered in Tamaulipas in 2011 for having reported on narcotraffickers’’ activities. The murders included that of María Elizabeth Macias, an influential blogger found decapitated on 24 September 2011 in Nuevo Laredo, a crime for which gangsters claimed responsibility.”