In the future, you may go shopping and pay a different price than someone else buying the same items — even just at the next register over from you. Unlike the already-pervasive array of price-discrimination tactics, this one will not be due to the volume of a product you purchase, what time you purchase it at, where you purchase it from, how often you purchase it, or even your age, occupation, or citizenship; rather, how much you pay may be determined by how much money you have. This individual sliding-scale fee system is already part of many school, medical, and law-service payment systems, but it could become the basis for every transaction with the advent of cryptocurrency.

A fundamental principle of many of the top cryptocurrencies is that of a public distributed ledger, or a blockchain. Multiple nodes on a blockchain cryptographically verify each transaction and update the rest of the blockchain so that every node knows the balances and transactions of all addresses, or wallets, without the need for any single trusted authority like a bank. This is logistically revolutionary, but its adoption may come with the unexpected effect of altering prices for each person on a transaction-by-transaction basis.

For the most part, consumers expect to pay what others pay when buying goods from the same retailer. Price tags affirm that. One Los Angeles restaurant called Everytable has experimented with this sliding-income pricing by store location, but even this has flaws. At such a coarse granularity, it fails to recognize the economic diversity within neighborhoods; for example, Venice, California has been the subject of the most rapid gentrification in the nation, spurred by tech companies’ inundation of “Silicon Beach.” The median household income for a beachside census tract in Venice increased from $48,393 (adjusted for inflation in 2013) in 1990 to $66,008 in 2013, with the likely beginnings of an exponential curve if 2018’s data were available. This has directly affected housing prices, with many occupants only able to maintain stable housing prices due to rent control. If all restaurants and grocery stores in Venice implemented the location-specific pricing that Everytable uses, low-income residents, and homeless people who are not accounted for in Census demographics, could be priced out — and if this model took hold nationwide, it might lead to an even more economically segregated country with areas of intense poverty and others of wealth, delineated by store pricing.

There is not yet a way for retailers to implement the fine-grained individual pricing that would solve this problem, though. Banks don’t tell stores your account worth. A naïve improvement to this is honesty-based pricing where a customer pays however much he wants, but this is not very scalable as it requires trust on the store’s part. Cryptocurrency is what almost changes everything. Everyone can see the balance of every wallet, but the problem is that nobody knows who owns a wallet — for the most part. Because fiat is the most common entry point for obtaining cryptocurrency, exchanges are required to know their customers and report US transactions to the IRS (in the US, at least). However, once you transfer that cryptocurrency from the exchange to another wallet, your personal balance is anonymous unless you’ve told someone else that you own that wallet. Herein lies one of the biggest hurdles to individual price discrimination, or first-degree price discrimination, and one of the biggest data-mining efforts likely being undertaken. Companies and governments who can create a whitespace, as venture capitalist Chamath Palihapitiya discusses in a talk at Stanford Business School, on top of cryptocurrencies to map wallets to identities can know how much money you have and track whom you send money to and receive money from. However, one last obstacle to this is that people can have as many wallets as they want in a system that can generate a near-infinite number of addresses. This last hurdle can be solved by technically limiting the number of wallets someone can generate or through government policy, and with that, everything that would be needed to implement individual price discrimination would be satisfied. In fact, this last hurdle is far from absolute since there already exist tools to track funds between accounts and infer account holders with high probability.

Therefore, it is clear we are at a fork where the cryptocurrencies we decide to support and put our trust in may determine the future of our financial privacy. Whether you like the idea of individual price discrimination or not, you are voting by investing in coins like Monero that anonymize all transactions or Litecoin, which plans to implement an anonymizing feature, or investing in others that prioritize other features. Some argue that anonymizing transactions opens the door to crime like buying illegal drugs and weapons while others like Chamath Palihapitiya argue regulation doesn’t stop it. Are we creating tools with the potential for even greater surveillance than we are under today? Can companies be trusted to make pricing decisions that don’t hurt the lowest income classes? Should cryptocurrency be subject to more stringent regulation?