Times have changed in Buenos Aires, security has been reinforced in the train and subway lines to cope with the magnitude of graffiti. The guards are armed and the police no doubt organize ambushes, so led to a radicalization of the actions. Palanca technique has become common to achieve the goal. In Sarmiento commuter line, twenty writers attack a train station with an armed guard, but the action did not turn out as expected.

(Via)