The author fails to understand that fungibility is tangential at best to anonymity. fungibility is based on the equality of a unit of stuff. short selling works with fungibility, you hire some shares of IBM. Once you have them you sell them, when the price drops you buy them back. The hire period ends and you return the same number of shares, but not the same shares. This works because it is agreed that shares of the…
one stock is the same as others, but you can have tainted coins that you obtained through legal means (it is just that the source was invalid). With BTC exchanges can block cashing out, for example.
Thats the same for stocks, trades can be reversed, this happens quite often.