Parag Agrawal: 严峻的挑战是，许多表面上看起来是假的账户——实际上是真实的人。一些实际上是最危险的垃圾邮件帐户——并对我们的用户造成最大的伤害——在表面上看起来完全合法。

原推：The hard challenge is that many accounts which look fake superficially – are actually real people. And some of the spam accounts which are actually the most dangerous – and cause the most harm to our users – can look totally legitimate on the surface.
https://twitter.com/paraga/status/1526237583843287040