During the boom of 2017, we saw all sorts of projects and companies claiming to use blockchain for pretty much everything; this just shows an attempt to ride the hype wave. There were even cases such as the New York-based soft drinks company Long Island Iced Tea, which rebranded itself to Long Blockchain Corp, only to see its shares rise by nearly 500%. Such actions definitely don't help anyone, as the company was promptly investigated by the Securities and Exchange Commission (SEC).
Some of the other developments in the blockchain community were the multiple forks in the largest cryptoasset, Bitcoin, which we saw recently. Forks are basically splits in the network, resulting from differences in the software protocol being run by its participants.
We have seen various actors trying to drive their own versions of Bitcoin forward, and this has resulted in the creation of Bitcoin Cash, Bitcoin Gold, Bitcoin Diamond, Bitcoin Private, and Bitcoin Satoshi's Vision (SV), among others. Such developments may partly result from a desire to improve the protocol, but they also result from greedy attempts to achieve more control and extract more value from the internet of money. Effective governance of decentralized systems in the presence of multiple (and sometimes, contradictory) interests that have to be balanced is one of the most difficult problems that need to be solved going forward.
Going back to the key benefits of distributed ledgers, removing middlemen and quick and efficient transaction settlement are definitely right at the top. This can enable lots of interesting use cases, from payments and money transfers to property registers and capital markets. Such infrastructures can be public or private, the main differences being in the level of trust embedded in the system. A public network that is open to everyone, where parties don't know each other, needs a different level of security and a different consensus mechanism than a private, permissioned network, where parties are vetted before they are allowed to join. This will be discussed in detail later on.