On Thu, Feb 4, 2016 at 11:56 AM, jl2012 via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> past the triggering block. A block-chain re-org of two thousand or
>> more blocks on the main Bitcoin chain is unthinkable-- the economic
>> chaos would be massive, and the reaction to such a drastic (and
>> extremely unlikely) event would certainly be a hastily imposed
>> checkpoint to get everybody back onto the chain that everybody was
>> using for economic transactions.
>>
>
> No, the "triggering block" you mentioned is NOT where the hardfork starts.
> Using BIP101 as an example, the hardfork starts when the first >1MB is
> mined. For people who failed to upgrade, the "grace period" is always zero,
> which is the moment they realize a hardfork.
>

Are there any plans written down anywhere about the "hastily imposed
checkpoint" scenario? As far as I know, we would have to check-point on
both blockchains because of the way that hard-forks work (creating two
separate chains and/or networks). Nothing about this should be an
"emergency", we have all the time in the world to prepare a safe and
responsible way to upgrade the network without unilaterally
declaring obsolescence.

- Bryan
http://heybryan.org/
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