The brutal killing of Macias Castaneda in Mexico reportedly in retribution for her social media posts about drug cartels is shocking.

Castaneda was a newsroom manager for the Nuevo Laredo daily newspaper, Primera Hora, rather than a journalist.

Police are investigating whether she was targeted by a drug cartel for her posts on Nuevo Laredo en Vivo.

Two weeks ago, a young man and woman were also killed, reportedly as a warning to social media users who speak out against the drug cartels on social media.

The targeting of these people shows how the killing space in Mexico has extended from the physical border between the US and Mexico to the virtual space on social networks.

In his Peter Wall talk on Monday 26 September in Vancouver, UBC Professor Derek Gregory cited the border lands in Mexico as an example of how the venues for conflict have shifted over the past decade.

Talking about “the everywhere war”, Prof Gregory highlighted how the killing space today is not restricted to a conventional battlefield.

Instead he used the militarisation of areas on both sides of the US-Mexico border as an example of how the space for war has become far more difficult to define, especially with the US talks about conducting “war in countries we are not at war with“.

The attacks on social media users in Mexico reflects how this “everywhere war” is crossing into virtual spaces.

Just as the boundaries of war are being blurred in the 21st century, so are the boundaries of personal and public spaces.

In my introduction to Prof Gregory’s talk, I spoke of how the shape and conduct of information wars had changed over the past decade.

In the 20th century, you needed access to a printing press, to a broadcast station, to produce and distribute information to a mass audience.

Today, the tools for the gathering, production and dissemination of information are readily accessible – from the computer terminal in a public library to the smartphone in your pocket.

Digital, networked technologies allow citizens and organisations to take on some communication functions that were previously largely in the hands of powerful institutions.

Consider how Facebook and Twitter were used during the Egyptian uprising as tools to mobilize and organize protests, as tools for spreading word of the demonstrations and amplifying the message of resistance.

Parallel to the drama in Tahrir Square, an information war was taking place on digital networks. The Mubarak government was forced to resort to the drastic option of switching off the internet.

Of course, these new media technologies can be used both by people rising up against an authoritarian regime, and by the security forces seeking to prop up such a regime – Iran is a case in point.

In Mexico, the same social media tools that are being appropriate by citizens to fight the cartels are being used by the cartels to further intimidate the public.

This is the shape of the everywhere war of information today, where media technologies disrupt how we communicate, change our notion of time and space, undermine distinctions between the public and the private, and violence spans physical and virtual spaces.