Note: The author, Wang Po-Wei, reveals "Sandbox" as the only artwork in the exhibition Injector_before Null, and that on the site there is only a radio transmitter which is not placed at the spot proposed for the artwork, whereas the spotlights are unmistakably projected onto the spot for artwork. The condition deliberately created by the artist to contradict viewers' accustomed experience manifests the fundamental questions in art institution: What is the so-called (art) institution? Where is the art that resides in the society? What is the difference between the act to send SMS to mobile phones through physical telecommunication facility and hacking?