The e-ticketing systems of eight airlines, including Southwest Airlines and Dutch carrier KLM, have a vulnerability that can expose passengers' personally identifiable information, mobile security vendor Wandera has reported. They use unencrypted links that hackers can intercept easily. The hackers then can view and, in some cases, even change the victim's flight booking details, or print their boarding passes. Air France, Vueling, Jetstar, Thomas Cook, Transavia and Air Europa also have this problem, according to Wandera.