Well, in my comment I simply wanted to distinguish between state-run currencies and bitcoin.

> But fiat currencies are simply currencies that aren't backed by collateral

I've checked wikipedia, and one of the definitions for the term "fiat money" is "state-issued money which is neither convertible by law to any other thing, nor fixed in value in terms of any objective standard.". Bitcoin clearly doesn't fall under this definition. So your statement is not quite true.