[previously in sequence:List Of Fictional Drugs Banned By The FDA, More Fictional Drugs Banned By The FDA]

VatiCoin: After a thousand years, the Catholic Church discovered how to do indulgences right: as tradable digital tokens. Not only does an initial coin offering provide better price discovery than the Pope picking a random number, but sinners who do good deeds later can sell their coins to someone else. Subject of several court cases about whether someone’s VatiCoins go to their heirs upon their deaths or whether this would defeat the point; current holders are advised to avoid the problem by not disclosing the password to their wallet.

Banned because: Frequently used as a hedge against other cryptocurrencies involved in crime and pornography.

Driverify: Developed by Tesla’s self-driving-car division. Cars mine Driverify with spare computing power while idling, and spend it bidding against each other for right-of-way if they arrive at a four-way stop sign at the same time (users can preprogram how aggressively their cars bid in these auctions). Compatible Teslas would also have fenders that send electrical pulses, transmitting data into the receiver fender of another car. If two Teslas got in a fender-bender, they could use their now-connected fenders to have the at-fault car recompense the victim by transferring an appropriate amount of Driverify.

Banned because: in the Phoenix suburb where the system was being tested, a pedestrian and Driverify-equipped car reached an intersection at the same time. The car dutifully wired a bid, but the pedestrian failed to respond. The car interpreted this as a bid of zero and ran into her. The pedestrian might have survived, except that the car realized it was at fault and tried to wire a fortune in Driverify directly into her nervous system, causing cardiac arrest. Elon Musk agreed to voluntarily withdraw the project until Neuralink could find a way to make pedestrians Driverify-compatible.

RedCoin: Karl Marx always said that communism would be a non-hierarchical economic system that prospered after the state withered away. A group of Marxist intellectuals took the obvious next step and made it an altcoin. RedCoin is notable for its reverse-proof-of-stake; you get more RedCoin in proportion to how little RedCoin you have right now, ensuring that all wallets naturally tend toward an equal amount. You can’t do decentralized finance on RedCoin, but you can do decentralized linear programming calculations to determine the optimal allocation of goods in a planned economy.

Banned because: potential to destroy capitalism and usher in new era of broad-based plenty

ConTracked: A proposed replacement for government contracting. For example, the state might issue a billion ConTracked tokens which have a base value of zero unless a decentralized court agrees that a bridge meeting certain specifications has been built over a certain river, in which case their value goes to $1 each. The state auctions its tokens to the highest bidder, presumably a bridge-building company. If the company builds the bridge, their tokens are worth $1 billion and they probably make a nice profit; if not, they might resell the tokens (at a heavily discounted price) to some other bridge-building company. If nobody builds the bridge, the government makes a tidy profit off the token sale and tries again. The goal is that instead of the government having to decide on a contractor (and probably get ripped off), it can let the market decide and put the risk entirely on the buyer.

Banned because: Wall Street developed a financial instrument that let them short ConTrackeds, then tried really hard to prevent bridges from being built.

GenghisCoin: Distributed by proof-of-research; instead of using a random cryptography problem for proof-of-work, the Genghis protocol makes users solve a specific useful problem. In this case, the particular useful problem is mining competing cryptocurrencies with fewer users than GenghisCoin. Once GenghisCoin has mined enough of a competitor, it launches a 51% attack and redistributes the competing coin to its own users in proportion to how many GenghisCoins they have.

Banned because: one time someone used it to buy marijuana

Umanity: Computers keep taking our jobs; what if we turned the tables on them? Umanity uses a revolutionary proof-of-work algorithm based on CAPTCHAs. Each node generates a few letters of a CAPTCHA, then transmits it as a bitmap to other nodes, until they arrive at a full CAPTCHA by consensus without any of them knowing the whole answer. Once a human answers the CAPTCHA, each node cryptographically signs off on its own contribution until they agree the CAPTCHA is solved and issue an Uman to the solver. Instead of guzzling electricity and contributing to climate change, mining Umanity provides steady well-paying jobs to underskilled workers.

Banned because: Courts rejected Umanity’s arguments that its workers were independent contractors and made it reclassify them as employees; nobody could figure out how to decentralizedly give people paid time off and maternity leave.

BuffyCoin: Users receive BuffyCoins for slaying vampires; the more dangerous the vampire, the greater the payout. Vampire-slaying is verified through…wait for it…proof-of-stake.

Banned because: SEC controlled by vampires