David Amsler is part entrepreneur, part hacker. Businesses hire his company, Foreground Security, to break into their computer networks and expose potential security weaknesses. Then, Foreground Security helps clients plug the security holes. Amsler studied business in college, but computers have always been his passion. He launched and ran the cybersecurity division of an IT consulting firm for nine years before striking out on his own. Amsler launched Foreground Security to capitalize on the growing market for online security. "You can't open a newspaper without seeing another company being hacked," he says. To stay one step ahead of the bad guys, Amsler has to keep his team sharp. Every year, he holds several Capture the Flag contests, in which employees compete to be the first to hack into a server.