I think the concern here is what happens if someone finds your paper boarding pass and scans it. That's less likely to happen with a boarding pass on your phon

I think the concern here is what happens if someone finds your paper boarding pass and scans it. That's less likely to happen with a boarding pass on your phone. (though in general, the problem of airlines requiring very little information -- all of which is on the boarding pass -- to be able to access an itinerary and make changes or cancel it is somewhat well-known among frequent flyers)