The plaintiffs were injured in a car accident after the tread on a tire manufactured by Cooper Tire & Rubber Company (Cooper) (defendant) came apart. The plaintiffs sued Cooper, DaimlerChrysler Corporation, and DaimlerChrysler Motors Corporation (defendants) in strict products liability, negligence, and breach of warranty. The plaintiffs claimed Cooper knew or should have known that its tires were likely to separate, but purposefully did not change its design or warn customers. During discovery, the plaintiffs sought information from Cooper to substantiate their claims. Cooper filed a motion for a protective order on the ground that the plaintiffs’ demands were excessively broad. Cooper requested that discovery be limited to the design of the type of tire at issue, the manufacturing plant at issue, and a reasonable period of time before and after the manufacture of the tire at issue. The plaintiffs filed a motion to compel. The magistrate judge denied Cooper’s motion and required it to produce the requested discovery. The district court affirmed the magistrate’s rulings. Cooper appealed, seeking a writ of mandamus vacating the order of the district court and requiring the district court to apply Rule 26(b) of the Federal Rules of Civil Procedure in its discovery ruling.