I know about the USB devices that have a write protection switch that disables writing on the device side, are there devices that have a similar hardware switch that permanently erases the devices memory, or another method that can verifiably erase the data?
After watching this video I got the feeling that even snapping a micro SD card in half may not permanently erase the device, so I was looking for an alternative.
A switch or method to irreversibly destroy the memory could also partially answer this question but I worry that it would be harder to verify, since it is a trick you can only do once. Even devices that have a self destruct method of forgetting the devices encryption key require some trust from the user and the device to be plugged in at the time, the best answer would be a button that resets all the memory to 0.