Continuing the discussion from Push Back on NameDrop Privacy Insinuations:
Well, it’s definitely not a hoax. It was demonstrated at the DefCon hacker conference many years ago.
But that having been said, although it is possible, I don’t think it is very common.
But my routine is such that I rarely if ever need to use a public charger. I charge at home and in my car. It’s only when traveling by air or train that I need to charge my phone on the go, and most of the time there’s an AC outlet available. And given the small size of portable chargers (e.g. the little 5W cubes that Apple sells), I consider it a no-brainer to just bring one with me when I’m traveling.
But that having been said, there are occasions where I have no choice. A recent international flight did not have a working AC outlet under my seat, so I used the USB port next to the seat-back video screen. But I consider the odds of a major airline getting its in-flight equipment hacked to be pretty low.
But if this is a concern, you can get a USB data blocker dongle. This will let you charge your phone while blocking all data transfer. If you spend a lot of time charging on-the-go from random/untrusted sources, you might want to get one.
See also: