Recently, I came across a topic that’s really worth a deeper discussion—what ordinary people should do if they suddenly receive “black U.” This issue is more common than you might think.

First, let’s look at the current situation. Crypto-related crime is on the rise, and illicit actors especially like to use USDT to operate. Why? I’ve summarized it in three points. First, liquidity is too strong. The amount of USDT issued on the Tron network has already exceeded 50.8 billion, and the daily trading volume is over 30 billion, which means illicit actors can quickly move “dirty money” out. Second, the ecosystem is complete. USDT supports both centralized exchanges as well as DEX and DeFi, leaving too many options. Third, fees are cheap. Compared with Bitcoin and Ethereum, the costs on the Tron network and Layer 2 solutions are much lower—making them very attractive for illicit operations that need to process large volumes of transactions.

That’s why the “black U” problem is getting more and more serious. Ordinary users may face account freezes or even legal trouble just because they accidentally received risk funds from an unintended transaction. I’ve seen plenty of such cases.

But there’s a positive change—Tether’s attitude is shifting. In the past, many people thought USDT was anonymous and safe, but that’s not true. Now, Tether is collaborating more closely with law enforcement agencies. They can directly freeze funds on-chain and even add addresses to a blacklist. This has made illicit actors realize that USDT is no longer a perfect tool for laundering money. Some escrow and guarantee platforms in Southeast Asia have started screening funds and refusing to receive money involved in serious crimes such as drug trafficking and scams. Even illicit actors themselves have started to know that USDT carries risks.

Someone asked: is USDC safer? In theory, it might be, but in practice it’s hard. Because USDT appeared earlier and has a more mature ecosystem, everyone is used to it. Illicit actors are the same—they’ve already built an entire workflow and won’t easily switch. This is what’s called path dependence.

So how can ordinary people protect themselves? Here are a few suggestions.

First, don’t trade in high-anonymity scenarios. Those Telegram platforms without KYC may look convenient, but risk funds are especially likely to flow there. Second, stay away from online gambling. Gambling platforms usually don’t do KYT screening, and their fund pools are easy to have used to launder “black U.” Third, don’t be greedy. The so-called “low-price U” or “discounted U” are all “black U.” Fourth, use tools to check. Address-risk monitoring tools like MistTrack and Detrust can help identify many problem funds—by checking the counterparty address before trading.

Exchanges are also taking action. Large exchanges are improving KYT and anti-money laundering mechanisms, communicating with external partners, and supplementing regional risk data. Smaller exchanges are also seeking help to build their own AML systems. This is a good trend.

But there’s a contradiction here. As anti-money laundering pressure keeps increasing, decentralized protocols are starting to be affected too. I’ve seen people transfer funds via cross-chain bridge protocols, only to have the funds frozen afterward—because the protocol’s business address was under regulation by centralized exchanges. This shows that even decentralized things may still get caught in the crossfire if they have contact with centralized systems.

So the problem today has become more complicated. Exchanges and institutions need to ensure funds are clean, but how do you tell whether a piece of money is truly clean? If a platform knowingly provides services to black or gray-market activity, even if it’s legal in some regions, its funds may still be regarded as problematic. This is a challenge for the entire industry.

Overall, the “black U” problem won’t disappear, but the situation is changing. Illicit actors are adapting to regulation, and we need to adapt too. The key is to stay vigilant—don’t fall into traps just because you’re chasing a cheap price or you don’t understand the risks.