Story co-founder: The 20-point airdrop limit for Passport is modeled after the drinking age restrictions in American bars.

Odaily Planet Daily News: Regarding the requirement that "Story airdrop participants must meet a score of 20 on the Passport platform," Story co-founder Jason Zhao added in the comments section: "Being 21 years old and above is the legal age for drinking in bars in the United States. A score of 20 or above allows participation in Story's reward collection."