Circle overlooked a cryptocurrency theft from decentralized exchange aggregator and liquidity provider SwapNet and failed to freeze the stolen USDC (USDC) stablecoins.
On January 25, a hacker exploited a vulnerability in SwapNet's smart contracts on the Ethereum blockchain's second-layer Base network and stole $16.8 million worth of digital assets. To launder the stolen funds, the criminal exchanged $10.5 million USDC for 3.655 ETH and began transferring the coins to the Ethereum mainnet, apparently for subsequent legalization through crypto mixers such as Tornado Cash.
A blockchain sleuth known by the pseudonym ZachXBT expressed outrage at the inaction of Circle employees:
Experience shows that Circle is a lousy company. Approximately $13 million worth of USDC was stolen from SwapNet's smart contracts 10 hours ago. The attacker's crypto wallet still holds $3 million worth of USDC, which can be frozen.
Why would anyone develop USDC-based products if they don't care about their customers?
As Happy Coin News has discovered, Tether, the issuer of the Tether (USDT) stablecoin, is taking its fight against criminals much more seriously. This is evidenced by the fact that from the beginning of 2023 to December 2025, Tether locked up 30 times more digital assets and froze coins 20 times more often.
USDT is only 160% larger in market capitalization than USDC, so such a huge difference in the scope of sanctions imposed cannot be explained solely by USDT's greater popularity.