Is there evidence to support the theory that most zero mixin usage (when allowed) came from exchanges? If so do we know if their reason was:
- Attempt to save on transaction fees
- Indifference to untraceability of transactions
- Attempt to make it easier to track withdrawal transactions for customer identification or support purposes
Are there any known exchanges that voluntarily used non zero mixins for withdrawals (thereby enhancing user privacy) prior to being required by the protocol to do so?