In 2004, a man named Orin Safier bought an 80 GB hard drive. His computer reported 74.5 GB. He wanted the missing 5.5 GB back — or his money. The case, Safier v. Western Digital , became the legal test for a question that has annoyed every computer buyer since the 1980s: why does the operating system always report less storage than the box promises? Western Digital's defense was simple, and it was legally correct. The drive contained exactly 80,000,000,000 bytes. Western Digital defined...