Airlines Use Digital Technology to Get Even More Personal - NYTimes.com

Not sure it's "a very fine line"

"“Using technology to position itself as a forward-thinking airline can have a positive impact on preference” among fliers, said Henry H. Harteveldt, a travel industry analyst in San Francisco for Hudson Crossing, a consulting firm. “But there is a very fine line between cool and creepy.”
One airline system that delves even more deeply into business travelers’ data was rolled out late last year by the Australian carrier Qantas Airways. It enables Qantas to monitor, in real time, social-media conversations taking place within its airport lounges."

Airlines Use Digital Technology to Get Even More Personal - NYTimes.com