The safety of roller coasters, especially the newer generation of them, has recently been the subject of controversy. Since 1979, more than a dozen people have sustained serious brain injuries on roller coasters, and one elderly patient has died. One medical study, however, found that even the most spectacular roller coasters exerted no greater G-force on the brain than “plopping into an easy chair,” far less than the force needed to tear brain tissue or cause swelling. Critics of this study note that its conclusions apply only to normal, healthy individuals, and that it says nothing about roller coaster safety for people with preexisting medical conditions. Should roller coasters be permitted to operate? Why or why not? How should they be regulated? What liability rules should apply?