What will life be like when digital brains outnumber humans?

These days, people worry about robots stealing our jobs. But maybe we should be more concerned about massive populations of computerized human brains. Called "ems," these infinitely-reproducible brains could change the world. Here's what will happen when digital brains vastly outnumber biological ones. » 2/24/14 11:00am 2/24/14 11:00am