Maybe do the final withdrawal to the user's public withdrawal address if one is set, otherwise to the address of the last successful withdrawal?
That makes sense. I will write the script so that it pulls that first, then falls back to the last successful withdrawal.
Second, and a little harder... what to do with the deposits that do not get withdrawn before the site shutdown:
In a perfect world I'd like to hold the deposits 6-12 months so that people could continue to make claims and withdraw their forgotten coins. I do not believe I am going to be allowed that luxury. Thus, despite the risks, I suspect I am going to have to process refunds back to the address of a user's last successful withdrawal. I know this is not ideal. Some portion of the withdrawals are going to go to addresses that are no longer used, or are on sites no longer in service... Can anyone think of a better alternative?
Maybe donate to the Bitcoin Foundation? I think that's a better alternative than loosing the coins to unused addresses.
The thought definitely occurred to me, but then the people who were not aware of the shutdown (maybe went on a 6 week trip to the Antarctic?) are essentially forced to donate their coins. So which is worse?
Antarctic Voyager A, lost his address, coins go into a void.
Antarctic Voyager B, happily receives his coins.
-or-
Antarctic Voyager A, coins went to the Bitcoin Foundation, he's happy.
Antarctic Voyager B, coins went to the Bitcoin Foundation, he's pissed.
I do think I might be able to hold the funds for another 30 days past the go-dark date, so I can buy a little time, but sooner rather than later I have to deal with it.