Your telephone is running low on power while you wait to fly out of an airport. Other people have connected their cell phones and other devices to electrical outlets in the waiting area. Like you, they are preparing for the flight. Then you discover a public USB charging area close by. You quickly reach for a charge cord and connect your phone to the charging hub. Then you take a deep breath and sit back, happy to get the power for free. What could go wrong? Plenty. In addition to providing electrical current, phone charge cords can send and receive data. That free USB charging hub at an airport, hotel or other public place may not only charge your phone. It also could be transferring information to and from the device.