A journalist found out the hard way that in-flight wi-fi isn't necessarily secure.
In a column for USA Today, Steven Petrow wrote that he had been working on a piece about the standoff between Apple and the FBI, while on a three-hour American Airlines flight from Dallas to Raleigh.
As the plane landed, a man in the row behind approached him and said, "I need to talk to you" and asked if Petrow was a reporter.
The man asked Petrow to meet him at the gate and continued to ask questions about his job and interest in the Apple/FBI story.
"I hacked your email on the plane and read everything you sent and received. I did it to most people on the flight," the man told him.
Petrow wrote that the man had verbatim detail of a long email, which he repeated back to him.
He told the MailOnline that he was "really shocked and couldn't believe this could happen".
"I think my face really fell to the floor in the terminal because very quickly he was reiterating to me in great detail what I had written in my emails," he said.
American Airline's wi-fi service is provided by Gogo, which is the biggest on-board wi-fi provider in the US.
Its clients include Air Canada, Japan Airlines, United Airlines and Virgin Atlantic.
Andrew Ferguson, editor at London-based thinkbroadband.com, told the MailOnline that in-flight wifi was similar to a public hotspot and should not be considered private.
"This problem is something not unique to just in-flight wi-fi, but to any public wi-fi network that is not encrypted," he said.