This is a bandaid that avoids solving the harder problem of trust/spam. It is such design patterns that make a fundamentally open/federated protocol more centra

This is a bandaid that avoids solving the harder problem of trust/spam. It is such design patterns that make a fundamentally open/federated protocol more centralized, exacerbating the problem. Personally, I think the use of proof-of-work like methods can mitigate the problem by a large extent, making it computationally expensive to spam users. This was one of the original goals of what has now become the "blockchain" revolution. Is anyone aware of any projects that are still implementing similar (open) systems?