> Blockchains are not implicitly related to "coins" ... That was definitely an oversimplification, and a slightly wrong one at that. In bitcoin, there isn't

> Blockchains are not implicitly related to "coins" ... That was definitely an oversimplification, and a slightly wrong one at that. In bitcoin, there isn't actually a concept of "coins". Just transactions which spend numbered UTXOs. If I'm remembering correctly, the term "block chain" came from a conversation between Hal Finney and Satoshi Nakamoto about Bitcoin. If so, one could argue that it IS implicitly related to cryptocurrency. That being said, the underlying "block chain" data structure is just an alteration of a previously existing data structure called a Merkle Tree which has data blocks that can be used for things that are not transaction data. Blocks in a blockchain have a payload section reserved for transaction data. Theoretically you could put anything in the payload section but if you're calling the data structure a blockchain, people are probably going to expect transactions in it. > I assume you could build a mastodon like that distributes and "authenticates" posts via a blockchain - perhaps with terrible performance though. This has already been done many times actually and it's quite impressive. Basically, a cryptocurrency full node is modified to serve as a social client and an appropriate user interface is built on top. The mechanism by which cryptocurrency transactions are shared with other validating nodes is the very thing that keeps user's "streams" updated and in sync. It has some major drawbacks but performance doesn't have to be one of them. With UTXO based blockchains like bitcoin, the "mempool" portion of the client code receives transactions containing social data embedded within. This means they are able to show the social media content immediately upon it being sent, even if the transactions containing that data have yet to be included in a block. One problem though, is that like transaction data, the social data doesn't get "finalized" until it's included then mined in a block. So you'd be able to see the messages in your feed but the content might change ten minutes later after it's finalized. In my opinion, the Achilles heel of blockchain based social media is the Achilles heel of so many otherwise brilliant technologies: "What is someone uses it for child porn?" Otherwise, most of the other drawbacks can be dealt with.