Is Mastodon really decentralized and censorship resistant? what if amazon or any cloud provider decide to go after some or all the instances like it did with parler? i think a master piece is still missing like IPFS or STORJ on blockchain as decentralized storage filesystem, i think also that we should look at some early decentralized application like emails and learn from the mistake's that allowed Google as gmail and MS as hotmail and yahoo to takeover by implementing restriction on who is allowed and not to send emails, now day's even if you implement all the good practice ( domainkey, spf...) you'll still not be allowed to direct message to inbox unless the IP is warmed up for few month's or years or whitelisted explicitly. fighting spam should also be thought in a decentralized way.