Tether and Circle can freeze addresses suspected of fraud, sanctions, or theft. Blacklisted addresses cannot send or receive tokens.
Calls blacklist functions directly on each stablecoin smart contract via public RPC nodes. No data is stored.
USDT: Ethereum, Tron (only chains where Tether enforces blacklisting on-chain). USDC: Ethereum, Arbitrum, Base, Optimism, Polygon, Avalanche.