When facing sudden rule changes or fraud during airdrops, investors should:  
1. **Document Evidence**: Save all communications (emails, tweets, whitepapers) and transaction records as proof of original terms.  
2. **Engage Community & Team**: Raise issues in official channels (Discord, Telegram) and demand public clarification; collective pressure often prompts responses.  
3. **Leverage Legal & Regulatory Paths**: File complaints with crypto监管机构 (e.g., SEC, FCA) if fraud is proven, attaching evidence of misleading promises.  
4. **Minimize Losses Swiftly**: Withdraw remaining funds from suspicious contracts/websites immediately and report phishing links to platforms like Etherscan.  
5. **Share Warnings**: Alert communities via Twitter, Reddit, or DeFi watchdog forums to prevent others from falling victim and pressure projects to act responsibly. Focus on proactive risk mitigation rather than recovery, as decentralized projects offer limited legal recourse.