Proposal to burn outputs from sandblasting transactions if not spent within a year

[daira]

Proposal: if you have any money in transaction outputs that appear to be in sandblasting transactions (by some criterion designed to absolutely minimize false positives and limited to the sandblasting period) then they have to be spent by a year from now, otherwise they will be burnt. That way they no longer need to be scanned after that year.

The cost of all other outputs is insignificant compared to the spam.

[daira]

I'm not specifically proposing that this be in NU7, but if it were to take effect after zcashd deprecation / NU7 activation, it would not need any changes in zcashd.