Baz Dreisinger visited prisons in nine countries and wrote about her experiences in a new book, "Incarceration Nations."
The United States has a near monopoly on armed drones, and it uses the technology aggressively in the hunt for Al Qaeda in Pakistan and Yemen.
But the U.S. could soon lose its edge, as both China and Iran test drones, with groups like Hezbollah and Mexican drug cartels lining up as potential customers.
Security experts have also raised concerns that other countries could follow America’s lead, and deploy drones across national borders in the interest of national security.
Robin Young and Jeremy Hobson are hitting the road. Our Tumblr brings you behind the scenes of our election coverage.