"The Social Network" is a horror movie. It doesn't shed a drop of blood, yet it manages to conjure some of the dread we feel when faced with a scenario -- any scenario, petty or grave, fictional or real -- that we are powerless to stop. It's about the gleaming new stadiums that rise up in major cities every few years without fail, despite protests and lawsuits and complaints to the zoning board. It's about finding out that you owe more in taxes than you expected, thanks to code changes hammered out behind closed doors by parties with deep pockets and a vested interest. It's about revisiting a cherished stretch of public beach for the sixth or seventh year running, and finding it fenced-off and swarming with cement mixers and guys in hard hats. And it's about how the United States avenged an attack by invading a country that had nothing to do with it.