All centralized platforms that want to control the content, but this is not actually a requirement of an online platform. Spam in e-mail is a problem because s

All centralized platforms that want to control the content, but this is not actually a requirement of an online platform. Spam in e-mail is a problem because spam consists of private messages sent to individuals, but public messages can be quickly categorized by a community, and ones own characterization of a message for the purpose of sorting messages for display can be based on a how whether it's chosen for retransission by people who who one oneself has a high trust in. Imagine having a feed which is initially a horrible spam-filled mess, and then as you encounter things it you like, you upvote that, until your feed is resorted to include mostly quite interesting things. When you again find spam or uninteresting content you reduce the weight of the people who retransmit it. Moderation always risks being political manipulation, and it's probably too dangerous to democracy to allow it. It's certainly too dangerous to accept foreign moderation (I'm from Europe).