A handful of SDN-outlined pools even now have an “operator” permission. Of these, two belong to quite previous, now-unused versions of Tornado Cash. The remaining pools possibly have more recent, immutable versions, or were being used so little which they have been probably ignored during the Could 2020 closing update. https://19zww.com/how-tornado-cash-enhances-privacy-for-ethereum-and-bnb-transactions/