A remotely related idea that I was thinking about a while ago, which came back to my mind while reading Vitalik's "Hard Problems in Cryptocurrency" blog post th

A remotely related idea that I was thinking about a while ago, which came back to my mind while reading Vitalik's "Hard Problems in Cryptocurrency" blog post that I found here[1], yesterday. Specifically the problem of spam is a special case of a Sybil attack[2]. People usually tend to be better behaved in real life than they tend to do in online anonymous/pseudonymous settings. Tying the two in a privacy sensitive way might be the way to go. IMO, any attempt at verifying that people actually did go out on a date after matching on a dating app would be a rich signal that the user(s) are not spammers or bots. The UX for this could perhaps take the form of a QR code that one could scan from their date's phone (or vice-versa). [1]: https://news.ycombinator.com/item?id=21618079 https://news.ycombinator.com/item?id=21618079 [2]: https://en.m.wikipedia.org/wiki/Sybil_attack https://en.m.wikipedia.org/wiki/Sybil_attack