Among non-lost coins I agree however "lost" coins will never be automatically sunset or moved by the owner to strong addresses because they are lost.  

Even then I am not saying action IS REQUIRED just that it MAY be required and certainly should be analyzed at that point.


The market will always adjust to the equilibrium price however such adjustments can be disruptive if there are large increases in supply or demand.  Those disruptions themselves can be damaging to the currency.

The other risk is that eventually "treasure hunting" becomes a more profitable venture that protecting the network.  Obviously that is in no-ones best interest.  Once again not saying it WILL happen but imagine a situation where ECC is significantly compromised.  As Bitcoin increases in value, the cost to brute force one private key falls (both due to deeper crypto flaws and Moore's law) the BTC per "GH/s equivelent" will rise.  If it is ever higher than block reward then it becomes more profitable to treasure hunt then protect the network.  Miners likely will do that leading to a tragedy of the commons scenario.  They may even form large hunting pools to reduce variance.

Still discussing it now is premature.  We don't know if ECC will be compromised.  We don't know how long such a compromise will take, we don't know how many coins will remain in compromised addresses.  If may never become "economical" to hunt for lost coins.  Even if it becomes economical the rate that lost coins are found may not be disruptive.  I am just saying that if ECC is compromised there MAY be a need for sunsetting compromised addresses.

If we did need to sunset "legacy" addresses I would advocate for permanent coin destruction rather than confiscating.  It removes the moral hazard.

The issue with the thread is it seems to things which are unnecessary are being advocated:
a) sunset addresses even if no compromise occurs
b) confiscate the wealth

Even if you agree that massive market disruptions are damaging neither are needed.  If the coins are spent after long inactivity and addresses algorithm isn't compromised then the coins were never lost.  It would be no different than Satoshi today dumping 1M+ coins on MtGox.  While not the smartest decision nobody has a right to say he "can't" and we need to confiscate the coins to make sure he doesn't.    If ECC algorithm isn't weakened there is no risk of large amounts of truly lost coins being "found".

On confiscation of wealth that is just asinine.  If the risk is not knowing if coins are truly lost then simply make them permanently lost with no profit to anyone.  The network doesn't need to have exactly 12.00000000000000000000000000000000000000000000 M BTC in circulation.   Giving the wealth to someone else creates a moral hazard.  Just destroy the coins instead.