The Mexico City megalopolis exists as a social and physical space, as a demographic ordering and disorder, but also in the forms imagined every day by the press, radio and television. These media organize the invisible communities of their public, which are informed through the media about the city, and they sometimes participate with reader’s letters or in phone-in programs. How is the public sphere reconstituted in these communicational circuits? Do the media contribute to the transparency and democratization of the city, or do they simply reproduce urban common sense?