But why not stop those bitcoins from being traded ASAP.
You keep (intentionally) ignoring this question. Who would do this? On what authority? How would they do it?
In related news the top 500 bitcoin addresses are mine and were just stolen please freeze them.
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 dont 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 dont think this matters you dont 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?
...
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?