Vitalik Buterin, co-founder of Ethereum, wrote that airdrops are an interesting initial use case for verifying zero-knowledge proofs (ZK), blockchain identities, credentials, and proof frameworks. He pointed out that the goals of airdrops include: distributing to random users who are members of the community rather than immediately selling, rewarding project contributors, maintaining relative fairness (allowing for some degree of differentiation), and defending against malicious extractive arbitrage. Buterin believes that these are exactly the characteristics that identity, credentials, and proof frameworks are designed to achieve, so it makes perfect sense to use token issuance as an initial use case for these frameworks to test and optimize, especially in adversarial environments.