There are 3 elements here.
1. Bitcoin used as a currency for purchases.
2. Bitcoin as an non-interest earning savings mechanism
3. Speculation on the price of Bitcoin, and the receipt of interest on lans.
1. Should not be taxed, even if people make a bit of profit from it.
2. If you tax this, then you need to tax fiat as well.
3. These are trading profits, and should be taxed like any other profit source. You should be able to offset losses as well.
My main use of BTC is as 1. I do however pay taxes whenever I convert to FIAT, not a huge amount but still, it does feel unfair sometimes.
