Security will be a major issue but no more of an issue than for electronic banking.
Are you kidding ?
In "electronic banking" there is almost no way anyone can steal significant amount of money without beeing caught and the money recovered.
I agree with ghdp.
I was at a $20 bn boutique fund the other day talking BTC with the owners -- I looked around the office and noted that there really isn't anything anyone could steal. If a criminal walked in you could give him free reign -- what could he take? Client lists?
If he was REALLY clever he could figure out where to wore money....then what? He'd need to have a wire to a bank where he could wore it to another etc. Opening anonymous Swiss bank accounts to receive a $10 mm wire the next week is purely a product of the movies (or maybe might have worked in the 1960s) -- there is almost no way people could move real money like that.
Bitcoin on the other hand -- all someone needs is to take a photo of a private key.
The Die Hard comment from DPoS is a real point! The reason we saw heists like the Lufthansa heist in the movie Good Fellas (which was a real heist) stop is not because criminals got more honest but because there isn't anything to steal. Now, with bitcoin there is again and when we talk $10, 20, 100 million worth... All bets are off....people have sent entire teams of heavily armed people to kill for a lot less. Not to be over-paranoid but I think Wall St. firms who think they can simply use the office safe and building security for 45,000 coins are making a mistake.