Keeping backups on CD's here and heard some usb pen drives have extra shielding that help withstand a magnetic pulse.
What pen drives are these as I'd like to protect all my data from an EMP
If there are EMPs occurring, the resilient pen drives will be worth far more than the resultant value of any bitcoins after that event occurs. (If for no other reason than the gold content of the electronics inside ... :-) )
Didn't see one, but i'm sure some devices encased in Permalloy or Mu-metal exist out there. The DIY solution would be wrapping the thumb drive with tinfoil, without touching the usb connector, and ground it somehow.