There is no doubt that every inch of public space is becoming increasingly scrutinized by microscopes intent on examining the maximum potential for attention and revenue. In the throes of an amorphous supply-demand model, which may inadvertently lead to a sanitized visual cosmopolitanism, public space remains a grayzone where visual battles from the top down and bottom up are waged every minute. While advertising is all too often a one-way visual avenue, effectively an imposition of conditioned images, a range of perceptible empty cracks in this visual economy inevitably leads to an excess which emerges in the periphery of this visual exchange between image and space. The Subpixel tool by F.A.T. (Free Art and Technology) facilitates a manipulation of printed materials such as subway advertisements. As the creators assert, Subpixel is "a tool made from laser-cut acrylic, rubber bands and nine razor blades," which can turn a "small patch of subway advertisement from a 'one-way, unending flow of shit' into an eight-by-eight grid of pixel stickers, now ready for two-way interaction with the public." With the nine parallel razors, taking two perpendicular swipes on a print creates a grid within which users can peel off cells as a visual hack - a new visual and interactive interface - one which the original 'authors' of the poster could have not imagined (will they, though?). Creating ripples throughout the economy of public space, Subpixel is not only a chance to reflect on advertisements and the autonomy of public space, but also presents opportunity for alert passers-by who can now interpret the hairline grid, or a de-pixeled poster as a call for (inter)action. Let the visual hacking begin. Vicente Gutierrez