An anonymous reader writes "After many years I now have a backup of all my digital data in (at least) two physical locations. But what do people recommend to back up my physical data? And then how to prove my identity? I call it the 'gas leak problem,' because a gas leak in my town caused an explosion that leveled a house. If it had been my house, it would have destroyed all my paperwork that proves who I am. If I'd come home from work and found my house was now a pile of rubble, how would I prove I lived there, knowing my key no longer fits the smoldering lock? If I'd left my wallet at home, my bank cards would have been destroyed so I couldn't withdraw money or book into a hotel. Or if I'd left my phone at the office, I wouldn't know anyone's number to call, or get anyone to vouch for me. What preventative steps can you take? Since having this nightmare, I've exported my phone's VCF file to an online repo, made online notes of all my bank account numbers and passport ID, I keep ICE numbers with me at all times (separate from phone/wallet), and I've hidden a spare mobile phone and house key in a box in a nearby field. But there must be more to do!"