The only serious concern I've found with Bitcoin so far is the probability that Satoshi has one or two million stashed away somewhere. That would represent up to 33% of current bitcoins and 10% of eventual bitcoins.
http://forum.bitcoin.org/index.php?topic=9745.20I can immediately think of two implications:
1. Bitcoin is vulnerable to massive market manipulation in the future by a single individual. This will deter anyone wanting to use a currency that floats freely in a market that's both unregulated and unmanipulated.
2. This could eventually represent an enormous amount of wealth. If the price rose to $10,000/BTC that's about the $20B that Larry Page is worth, so no problem. But if Bitcoin rises to be a significant fraction of the world's economy, that's a whole load of power in a single individual's hands. I hope Satoshi doesn't turn out to be The Joker.
It's a very important political economic problem for the bitcoin society to be solved.
I heard that the Gavin team still keep in touch with Satoshi through email, though Gavin don't really know who Satoshi is. Maybe Gavin should send a Satoshi a message, that we need him or her to give us a message, what he or she is going to do with his bitcoin. For the success of the idea, Satoshi need to sacrifice more. If he or she cares only about his own privacy or safety, the whole bitcoin will be suffered from panic again and again, just like what happened on the past weekend, an early miner had started to move about 17k BTC, then the market started panic selling.
And I really don't understand, why is anonymity so important for satoshi. The wikileaks are doing a more hostile-to-government job than bitcoin does, and Assange didn't hide from the public.
Why Satoshi hide? I want to hear some plausible explanations.
