A traveler discovered a way to access free WiFi for messaging on British Airways flights by signing up for their frequent flyer program through the captive portal. Through testing and analysis, they revealed that the airline uses SNI (Server Name Indication) to restrict the types of traffic allowed, allowing the traveler to tunnel arbitrary traffic by masquerading as messaging app connections. This led to a deeper exploration of TLS handshakes and the implications of SNI on privacy and data access during flights.