According to a Tokenpost report from South Korean media, stablecoin issuer Circle has blacklisted a smart contract address deployed on Ethereum tied to the privacy protocol Zama’s “Confidential USDC (cUSDC),” resulting in roughly $12.6M in USDC being frozen. The report cites on-chain investigator ZachXBT, who says the contract address had previously been publicly documented and viewable on block explorers, and that the freeze was observed in real time. One caveat worth flagging: the ”~$12.6M” figure and the “no prior notice” detail currently trace back to a secondhand Korean-language account. Neither Circle officially nor the raw on-chain transactions have provided a line-by-line confirmation yet. We treat this as “reportedly” pending, and readers should wait for primary sources before treating the details as settled.
Whatever the final numbers turn out to be, the technical substance of the event is clear: USDC contracts have a built-in blacklist function, and Circle, as the issuer, has the authority to unilaterally freeze any holding address. This is not a bug — it is a centralized control point that has existed in USDC’s design from day one.
Editorial take: will the USDC/USDT in your card wallet get frozen?
Short answer first: the overwhelming majority of virtual card users are unaffected. What got frozen was a specific DeFi privacy-protocol contract address — not an ordinary personal wallet, and not an exchange custody address.
That said, this is worth remembering as a boundary condition for every USDT card user:
- Cards funded via USDC — such as RedotPay, which supports multi-stablecoin top-ups — carry, in theory, “issuer policy risk” if the underlying settlement asset is USDC. That doesn’t mean the card itself gets frozen; it means that in extreme sanctions/enforcement scenarios, USDC carries one more layer of issuer discretion than USDT.
- Cards settled primarily in USDT — such as the editor-selected MPCard Asia Elite variant and Bybit Card — are less directly relevant to this specific event, since the frozen asset was a USDC contract. But USDT (Tether) has the same address-freezing capability, and on this point there is no fundamental difference between the two.
Expected timeline:
- Within 7 days: Everyday top-ups, spending, and refunds should see no change whatsoever. No card issuer will adjust its funding channels because a single DeFi contract got frozen.
- Within 30 days: Watch whether your usual card issuer updates its “supported stablecoins/chains” notices. Historically, after issuer-risk events, some platforms temporarily tighten deposits on a particular chain or asset.
- Within 90 days: If Circle later discloses that this reflects a new, normalized compliance-enforcement posture (rather than an isolated case), cards built around US-region USDC rails may adjust their settlement logic.
If you’re choosing your first card, the comparison dimension around “is the settlement asset USDT or USDC” in our 2026 U Card Top 5 is directly relevant to what this event has surfaced.
Historical comparison: this is not the same as the 2022 Tornado Cash freeze or the 2023 SVB depeg
To place this event properly, it helps to compare it against two historical benchmarks.
August 2022, Circle froze Tornado Cash–linked addresses: at the time, US OFAC sanctioned Tornado Cash, and Circle froze about 75,000 USDC within hours (the figure widely reported by multiple outlets then). That freeze had an explicit sanctions order behind it — the issuer was executing the law. In the current cUSDC episode, no public sanctions order has surfaced so far — if that holds true, it means the freeze threshold may be considerably more ambiguous than in 2022. That is the biggest difference.
March 2023, USDC briefly depegged due to Silicon Valley Bank (SVB) exposure: Circle disclosed at the time that about $3.3 billion of its reserves sat at SVB (a figure from Circle’s own statement then), and USDC briefly dropped to around $0.87 before the FDIC stepped in and the price recovered. That episode exposed reserve-bank risk — a question of “where is the money.” This episode exposes control risk — a question of “who can move your money.” Both point to USDC’s centralized nature, but they operate at entirely different layers.
The common thread: each event puts the same fact back on the table — the convenience of centralized stablecoins comes at the price of “the issuer can unilaterally intervene.”
Compliance angle: technical authority ≠ arbitrary abuse
The blacklist functions in USDC and USDT are, in most jurisdictions, legitimate compliance tools used to support sanctions enforcement, anti-money-laundering measures, and law-enforcement freezes. For ordinary cardholders with legitimate sources of funds, the probability of being caught up in this is extremely low.
That said, regulatory attitudes toward stablecoins vary widely across Asia-Pacific, and it’s worth weighing against your card choice:
- Hongkong has been advancing a stablecoin issuer regulatory framework since 2024, with clear requirements for licensed issuance — see the Hongkong compliance guide.
- Singapore’s MAS has established rules around stablecoin reserves and redemption — see the Singapore compliance guide.
- Japan applies a tiered licensing regime for stablecoins — background in the Japan compliance guide.
The current boundary is clear: it is a public fact that issuers hold the technical authority to freeze a given address. What remains disputed is whether this freeze happened “without notice and without a sanctions basis” — if Circle cannot later provide a compliance rationale, this will fall into the long-standing legal gray zone surrounding DeFi and privacy protocols.
Key milestones to watch
- Whether Circle issues an official statement: watch the Circle Transparency page and its official social channels to see whether it confirms the freeze and provides a rationale.
- ZachXBT’s primary on-chain evidence: if the original contract address and the freeze transaction hash are publicly verified, the “$12.6M” figure can be upgraded from secondhand reporting to a verifiable fact.
- Whether Tether responds: USDT underlies more USDT cards, so if Tether uses this episode to restate its own freeze policy, the impact on cardholders would be broader.
- Whether a second case emerges: whether a single-contract freeze is an isolated incident or a new normal will determine how much weight this story carries 90 days from now.
Editorial recommendations
- Users holding USDT-settled cards such as MPCard or Bybit Card: no action needed — this event has no direct bearing on your everyday top-ups and spending.
- Users funding primarily via USDC: there’s no need to panic-move funds, but it’s worth factoring “does my settlement asset depend solely on USDC” into your next card decision — compare against our 2026 U Card Top 5.
- All ordinary users with legitimate sources of funds: the blacklist mechanism targets addresses flagged for sanctions or enforcement action; normal top-ups and spending are not within its scope, and no “freeze-avoidance” action is needed.
- What not to do: don’t move funds into obscure privacy protocols or anonymous mixing tools in an attempt to “avoid freezes” — doing so is exactly what raises the likelihood of being flagged.
This event hasn’t changed how USDC or USDT works. It has simply made a design fact that was always there visible again: the convenience of centralized stablecoins and their freezability are two sides of the same coin.