The Callisto sexual assault reporting system is clever use of game theory. Two features of sexual assault reporting is that: 1) they are widely believed to be under-reported because victims fear being caught in a "he-said-she said" case that goes nowhere; 2) but when one victim comes forward, sometimes there are more victims who could come forward too. As Ian Ayres explains in the WaPo, Callisto encourages the latter without exposing victims to the former. It does this by allowing a victim to file contemporaneous accounts into escrow. These accounts will only be unsealed if the accused party is named by another victim. This means that, if accounts in escrow are ever unsealed, the case becomes a "he said; they said," which is often more successful in court.
Hat tip: Joel Waldfogel