[nojster]

That’s correct and several exchanges will freeze funds when they have a “tainted history”. Thus, tokens on open ledger DLTs are not fungible at all.

Cash is more fungible, yet you can also link serial numbers on bills back to ransom payments.

In a similar fashion, if you, even unknowingly, pay with counterfeit cash, you won’t get reimbursed for the face value, if it gets detected.

Back to crypto, Monero addresses the aforementioned issues through stealth addresses, ring signatures and ringCTs, thus fungibility of the token is higher.