Tom Kellermann got off a flight in Ottawa, Canada, when he noticed his iPhone acting unusual: It was trying to sync with unknown devices somewhere in the airport.
As a computer security expert who's worked at the World Bank, advised the White House and is now a vice president at Trend Micro, Kellermann knows the signs of a sophisticated hacking attack. And at that moment, he had no doubt he was witnessing one targeting him and likely everyone else in the airport.
Kellermann spotted the attack while poking around his phone's settings menu. He said the incident, which occurred a year and a half ago, changed the way he looks at air travel.
"Airports are supposed to be some of the safest places in the world - and they are in the physical sense," Kellermann said in a recent interview. "But they're also hunting grounds."
In fact, any place with business travelers and Wi-Fi -- such as hotels and conferences -- can make enticing targets for hackers.
By exploiting mobile devices as they try to connect to the strongest wireless signals, digital thieves can score people's contacts, e-mails and calendar entries. Such information can be used to figure out who's doing business with whom.
Since then, Kellermann leaves his devices on airplane mode all the way through the airport and even on train rides. The one time he didn't, he paid for it, he said.
He was on a train from New York to Washington last year when he realized he forgot to put his phone in airplane mode. By that time, it was too late. The phone had been rebooted and wiped of all its data, he said.
The culprit was likely someone stealing data from business travelers, he said. The incident wasn't surprising to him given the high volume of movers and shakers traveling that corridor.