It's surprisingly easy to alter anyone's airline reservations

Karsten Nohl and Nemanja Nikodijevic's Chaos Communications Congress presentation details their research into becoming a "Secret travel agent": they figured out how to force the various portals to the Global Distribution System to let them know if they've guessed someone's reservation locator code, which they can use to arbitrarily alter your flight plans, sending you to different cities, reseating you, or cancelling your flight. (more")