Yes, as someone else noted above, this pertains to taint. I'm curious whether the Foundation will support efforts to build databases of "tainted" (ie, banned/blacklisted) coins that entities can use to block transactions. I believe such systems run the risk of destroying an *essential* property of ideal money; ie, fungibility - the notion that one unit of the currency is the same as another, and can be sliced, recombined, and spent without issue.

Peter Vessenes was very pro-taint-database at the conference in May. I don't know if he was speaking on behalf of CoinLab, the Foundation, just himself, or some combo thereof, but his position was clear. I'd be interested to hear what Jon Matonis has to say about the issue in his new role as Executive Director of the Foundation.

To be clear, I'm all for bitcoin businesses fully operating within the bounds of the law. Fully open and compliant businesses will elevate bitcoin in the public sphere and get the currency into more hands. That's great for bitcoin.

What's not great for bitcoin is harming a core property of what makes it a fascinating and unique experiment. Bitcoin is ideal money for modern times, and fungibility has been a key property of good media of exchange for thousands of years. If that's eliminated or weakened, the case for bitcoin as a great money is eliminated or weakened, and this whole thing becomes a lot less interesting.