People tout the public ledger as a benefit of the block chain, but it's utterly useless as soon as someone converts to another currency and then back again (a.k

People tout the public ledger as a benefit of the block chain, but it's utterly useless as soon as someone converts to another currency and then back again (a.k.a. Tumbling). You mention bitcoin, and tumbling is exactly how money launderers and tax evaders use bitcoin's "public ledger" today.