Embedded into the façade of a tall office building in downtown San José, four digital yellow circles rotate every few seconds, seemingly without purpose. This display has gone on since 2006, and it could be easily dismissed as an unusual artistic choice by the resident of the building, the software company Adobe. But in actuality, this light installation, the San José Semaphore, is beaming a code across the city. The artist, Ben Rubin, replaces the code each time it’s cracked, which so far has happened twice. The first time, two tech workers…
