Source : Free On-Line Dictionary of Computing

Death Star
     
        ["Star Wars" film] 1. The AT&T corporate logo, which appears
        on computers sold by AT&T and bears an uncanny resemblance to
        the Death Star in the movie.  This usage is particularly
        common among partisans of {BSD} Unix, who tend to regard the
        AT&T versions as inferior and AT&T as a bad guy.  Copies still
        circulate of a poster printed by Mt. Xinu showing a starscape
        with a space fighter labelled {4.2BSD} streaking away from a
        broken AT&T logo wreathed in flames.
     
        2. AT&T's internal magazine, "Focus", uses "death star" to
        describe an incorrectly done AT&T logo in which the inner
        circle in the top left is dark instead of light - a frequent
        result of dark-on-light logo images.