Professional football is the most popular spectator sport in America, which is one reason the Super Bowl is expected to draw 110 million viewers. With its famous athletes, storied franchises and lucrative TV contracts, it's an industry whose future appears limitless.
But football has a problem: the specter of mass brain damage among current and former players. So far, the steady trickle of disturbing revelations has had no apparent effect on ticket sales or TV ratings. What it has done, though, is more ominous: It has invited lawsuits.