Airline delayed/missing/found baggage items. Once, the SITA database in Atlanta was bigger than google (10 years ago or so). A monopoly that carries extreme costs for airlines. All interaction via archaic terminals, with a few local GUI implementations. I've done one via piggy-backing, however if you're not a handling agent or airline then you're not allowed into the ecosystem. - I'm interested in pursuing this, but it's too large for me alone to handle.