Fungibility is fundamental to money. One dollar should have the same value as any other dollar. If I had to verify every dollar I accepted wasn't used in ille

Fungibility is fundamental to money. One dollar should have the same value as any other dollar. If I had to verify every dollar I accepted wasn't used in illegal activities, then it would undermine the fundamental principle of equal value units, the coins linked to the WannaCry hack are now less valuable because they're blocked by several exchanges, if you're unlucky enough to accept those coins then you're stuck with coin that is accepted in a lot less places. There's a reason why the "gold standard" was in a soft metal that could be easily reshaped and melted to fit standardised units and didn't corrode or "break" lowering its value, and not diamonds or gems, where each crystal has unique collection of properties, and thus market values, imagine having to have an assessor to be on standby check the value of every one of your customers gems or bitcoins. It's also fundamental that you should be able to go to a local coffee shop every day without the threat of being mugged by someone who saw your bitcoin wallet amounts, and your tx sending money to the coffeeshop enter the tx pool just as you buy a coffee.