Replicated here for discussion:

Czy ktoś z was próbował już opodatkować się w ten sposób?
Domyślam się, że potrzebny byłby jakiś papier na podkładkę dla Urzędu Skarbowego? Historia konta na Bitstamp to raczej mało oficjalny dokument. Z kolei potwierdzenie przelewu nie zawiera informacji o ilości zakupionych i sprzedanych bitcoinów.

I will only sell my last coin for 1 billion USD (in today's value).

I would encourage those who are attacking Burnside with anger to turn their attention to the "regulators" that are apparently threatening to bring force into a situation that is peaceful and consensual. It's hard to do this because we don't know exactly who they are. We do know that they feel they can't compete in a free market unlike Burnside who eagerly endeavored to do so. They feel they must threaten force to maintain their position instead of enticing people to cooperate as Burnside has. For this reason I wish the best for Burnside and the worst for the aggressors.

We should take our emotions regarding this failure and channel them into a sustained effort to architect a better securities exchange system. Bitcoin has worked so well because the architecture was decentralized and Satoshi was anonymous. We need apply these principles to the development of a more resilient securities market.