[squarefoot]

Hidden protected area in media + closed source software that writes it = potential tracking danger. I'm not implying anything, but putting those two things together could be dangerous.

Of course that should apply to all proprietary software accessing SD cards, therefore all phones, all cameras, etc; thankfully, being among the least reliable media out there for carrying files, and less practical than for example a USB connection or dongle, they're often restricted to the same hardware using them, as would be any potential tracking data.