I guess there's a law, otherwise why should exchanges care about were you transfer your money?
Oh I see, it must be a money laundering thing.
They can't tell how many you spent.
Can't they tell how many are associated with your address and thereby how many you've spent?
You only have to pay taxes when you cash them out. I would guess.
I'm wondering about this too. In the US, you have to pay tax on appreciated stocks even if you don't sell them. On the other hand, you don't have to pay tax on appreciated real estate until you sell it. What about BTC?
If I cash out some Bitcoins on Coinbase. I will add up all the money spent on Bitcoins and the amount of Bitcoins I have ever bought. Figure out the average cost of my Bitcoins. Then subtract that from the amount of each Bitcoin sold. To get the appreciation rate. Then if it is determined that I have to pay off the mafia government. I will do it (at gun point of course) to keep them from trying to steal my stuff.
Assuming taxes aren't due before they're sold (as with stocks) I think this is the best option too. It's just not worth it otherwise.
thing is they can follow the coins, but can they tie it to fiat conversion? isn't that what matters?
Which company that you trust with your BTC and fiat are you confident is not infiltrated by the US government now and will not be in the future?