On a related note, I wonder how much value is orphaned due to lost keys. If people forget their passwords, they can forget their keys/passphrases. Myself, I just had a hard drive failure. Of course, I have backups, but how many non tech savvy people are diligent about backups?<p>Considering the total amount of bitcoins is limited by design, this will eventually be a problem. I really dont think bitcoin is a viable currency for mainstream use.
I'm no bitcoin expert, but would it not be possible to cash out the below-fee-value coins by making a multiple-input transaction consisting of many wallets with <0.0004btc held, paying it all to one wallet, selling the contents of that wallet and returning the sale price back to the wallet holders?<p>Obviously that's pointless at the current fee level (<$1) but if the fee grows high enough, or if there's a way to reach these wallet holders en-masse and convince them of the value this would provide to the network (or get them to short btc in advance of a large sell-off of the gathered coins). Notwithstanding the legality/morality of any of this, it's not my field.
How can you say they are worthless, if all it would take is one miner to include all of those unsigned transactions in a block for them to have worth again?<p>It's one thing to say miners aren't incentivized to include them today. It's another thing to say no miner will ever have an incentive on any day in the future.