Failure to understand Bitcoin will indeed cost investors billions. 744,408 BTC stolen (nearly 7% of total mined coins to date) and some people seem to be cheering like this is a good thing because they don’t like (long despised) MtGox. This is far far from over.  Where did those stolen coins go? Well check your wallet because they were likely fed back to the markets. If you have been buying bitcoins on any exchange chances are you have some of the stolen loot yourself. These stolen coins can be traced back to their true owner in a direct chain of title thanks to the block chain. If you don’t think this matters you don’t understand the legal system and the principle of Nemo dat quod non habet

Under both American and English law the original owner of stolen property can demand ownership be returned to him if he can prove a chain of title (something the blockchain conveniently provides). The only recourse for an innocent buyer of stolen goods (and only in some jurisdictions) is to argue the exchange it was bought from had an implied warranty and he can try to sue the exchange after returning the coins to the true owner. MtGox is insolvent good luck there. BTC-e is run by anonymous folks think they will stick around in the face of massive lawsuits?

But cheer up there is still a chance most MtGox victims will get their coins back. The threat of massive unending lawsuits targeting innocent bitcoin buyers is an existential one for bitcoin. The 10-15 early adopters stand (by far) to lose the most if bitcoin goes down in flames. They might actually decide to buy out MtGox for the 744,408 bitcoins (an amount grossly exceeding the worth of the company) not because they are altruistic people, but because the chain of lawsuits that would follow if they don't act may hurt their holdings more than the loss of 744,408 bitcoins. It’s a lot of money, however, so its likely a difficult call for them. Regardless expect all future exchanges to require both rigorous identity checks prior to buying and selling as well as fine print stating that anyone who supplies coins to a market is ultimately responsible in the event those coins are determined to be “black” or stolen goods in the future.

Still think there is no need for truly anonymous cryptocurrency?

I hope readers can start to comprehend why coin taint is the most serious Achilles heel of Bitcoin.

On Friday, 2 BTC were stolen from me. I am considering reporting this to law enforcement. This means that anyone who receives BTC which derives from my stolen 2 BTC will be liable to return them back to me.

Perhaps the thief pushed them through a mixer such as Bigcoinfog.com

Thus that mixer will be liable to provide records. If it can't, then it will be liable for the 2 BTC.

So you can't you see you are playing with fire by mixing your coins through a centralized mixer.

And can't you see that without widespread anonymity (and decentralized mixers!), then crypto-currency is absolutely useless except to a government which wants a ledger from hell to track everything.