I have told people at airports to not friggin post their boarding passes or documents containing their booking refeeence on Instagram. Back when I was 20 I didn't lot of stupid things. One was to change tine obnoxious details about their reservations. When they were in air (and presumably had their phones off) I sent them a text message. "Never put booking information on asocial media".
Its more the airlines fault for making this info so easy to access with what looks like unsensitive info.