This paper advances the discussion about the interactions enabled through communication technologies by articulating Goffman's theory of strategic interactions and Trevor Pinch's concept of copresence, and applying them to analyze the way a Mafia's armed wing posted videos on YouTube during the turf war developed in Ciudad Juarez, Mexico, from 2008 to 2011. I analyzed the videos and the comments set up below them. Science and Technology Studies scholars have been engaged in a debate about how to study online contents. They agree that STS should advance approaches that only give an account of the semiotic properties of the contents, in order to explore the interactions they enable. However, they don't agree on how this should be done. This study lends support to perspectives arguing that Goffman's theory is still relevant to analyze online interactions, in spite of having written his theory before the expansion of the Internet. I provide examples to argue that, in fact, Goffman was fully aware that interactions could be technologically mediated. I suggest that members of the armed wing shaped YouTube's technological affordances to make themselves accountable to other parties in the war, and available for interaction. Goffman e o narco: como as propriedades técnicas do YouTube são usadas na guerra contra as drogas RESUMO KEYWORDS