According to @1HowardWu, every gas fee paid on a public chain leaves a traceable on-chain record that lets observers correlate the fee-paying address across interactions back to a single identity (source: @1HowardWu). Private-by-default chains can implement protocol-level gas abstraction so the fee payer is never revealed, blocking behavior aggregation and identity inference (source: @1HowardWu). For traders, this means wallet clustering, address correlation, and on-chain surveillance remain viable on public chains but are significantly hindered on private-by-default chains with gas abstraction (source: @1HowardWu). Traders should not assume encrypted transaction payloads alone provide anonymity if the gas-paying address is visible on-chain (source: @1HowardWu).