StarkNet combats **Sybil attacks** in its airdrop through **multi-layered verification**:  

1. **On-Chain Analysis**: Flags duplicate wallets with near-identical transaction patterns (e.g., same funding source, dApp interactions).  
2. **Time-Weighted Activity**: Prioritizes **long-term engagement** (e.g., bridging/holding assets for months) over sudden volume spikes.  
3. **Developer Proofs**: Requires **GitHub-linked contributions** (Cairo contracts, bug reports) for builder allocations.  
4. **Third-Party Data**: Cross-checks with **Ethereum mainnet history** to filter low-activity Sybil clusters.  

**Key Insight**:  
StarkNet’s approach targets **quality over quantity**—farming with 100 wallets won’t outperform 1 legit power user.