Definitions of death star  

1. The AT&T corporate logo, which bears an uncanny resemblance to the Death Star in the Star Wars movies. This usage was particularly common among partisans of BSD Unix in the 1980s, who tended 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 labeled 4.2 BSD 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.