A handful of SDN-outlined swimming pools however have an “operator” permission. Of those, two belong to very outdated, now-unused versions of Tornado Cash. The remaining swimming pools both have more recent, immutable variations, or were applied so small which they ended up probably missed over the May 2020 last update. https://trainthougths.com/the-ultimate-guide-to-tornado-cash-secure-and-anonymous-blockchain-transactions/