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From: Tom Harding <tomh@thinlink.com>
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Date: Sun, 20 Dec 2015 19:23:40 -0800
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Subject: Re: [bitcoin-dev] Forget dormant UTXOs without confiscating bitcoin
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On 12/20/2015 3:34 AM, Jeff Garzik via bitcoin-dev wrote:
> Ideally we should start having wallets generate those proofs now, and
> then introduce the max-age as a second step as a planned hard fork a
> couple years down the line.
>
> However,
> 1) There is also the open question of "grandfathered" UTXOs - for
> those wallets generated in 2009, buried in a landfill and then dug out
> 10 years ago
>
> 2) This reverses the useful minimization attribute of HD wallets -
> "just backup the seed"

Also, a change (#6550) has been merged to bitcoin core that removes
merkle branches from the wallet, and if pruning gets turned on (possible
in 0.12 with #6057), it would become quite a bit more difficult to spend
older coins under a change like this.

As a solution I would favor not removing wallet merkle branches.