Looks like Circle blacklisted the Zama (privacy protocol) Confidential USDC (cUSDC) contract on Ethereum 7 hours ago which has frozen 12.6M USDC of user funds.

The cUSDC contract is publicly labeled in the protocol docs and on block explorers.

Zama contract address frozen by Circle
0xe978F22157048E5DB8E5d07971376e86671672B2

It still remains unclear why Circle froze the USDC however in March 2026 I reported how Circle froze 16+ hot wallets for businesses, protocols, services without providing any transparency.