I am trying to follow you so where physical are you saying these private ledgers are held ?
20,000 servers all replicating 10,000,000 private ledgers and trying to keep in sync or
one copy in my wallet and a copy in yours if we are working without middle men (Banks)

The private ledger is 'multisig' so you can prove that I agreed to send you $1 worth in the IOU's we
are using in the private ledger and these IOU's are as good as gold because they are backed
by real BTC on the block-chain that are now locked (Cannot be moved)