Soundtrack to this post.
Last month, I wrote about evicting “Big Data” from my digital life. I migrated my entire digital ecosystem onto my own server. It went far beyond simple file storage; I now host my own search engine, media streaming, location tracking, and full personal cloud, reclaiming my digital sovereignty from the likes of Google and Microsoft. It was a technical challenge, but it was a battle I could win. If you own the hardware, you own the rules.
Stuck in a hospital bed, I have been researching how to apply that same logic to my weekly shop. This is not just an intellectual exercise. When I am discharged, I will be unable to drive for several months. My usual freedom to choose where I spend my money will be gone, shrinking my world down to walking distance. That leaves me with exactly one option: the Tesco just down the road. I would not normally choose them, but geography has made me a captive audience. Hoping to reclaim some agency, I thought I could code a solution from here, but I found the reality is far less forgiving.

We are all familiar with the “Clubcard Price.” You walk down the aisle for coffee or olive oil and see two prices. The first is a reasonable £6.50. The second, for non-members, is a punitive £11.00. For years, we have been trained to view the lower price as a reward, a discount for loyalty. But let us be honest about what this really is. It is not a discount. It is a Data Tax. The £11.00 is a fine you pay for refusing to hand over your identity.
I had a plan to circumvent this. Being a problem-solver, I thought about launching a service on this site: a “Communal Clubcard.” The idea was simple and socialist in nature. We would share communal cards, pooling our collective bargaining power to get the lower prices without giving Tesco our individual shopping histories. We would pollute their data stream with noise and reclaim the discount.
It turns out, they are way ahead of me.
I looked into the logistics, and the pitfalls are designed specifically to crush this kind of collective action. Tesco now uses “velocity checks” to detect if a card is used in Glasgow and London within the same hour, instantly locking the account. They have updated their scanners to reject screenshots of barcodes. They are phasing out physical cards in favour of apps that generate rotating, expiration-prone QR codes.
They have not just made it difficult to share; they have engineered the system to ensure a one-to-one surveillance ratio. They do not just want a customer to buy the beans; they need to know that Douglas Ireland bought the beans, at what time, and what he bought alongside them.
This brings me to a depressing realisation. I can self-host my email. I can self-host my photos. But I cannot self-host my groceries.
In the digital world, open-source software like Nextcloud offers an escape hatch. If you have the skills and the patience, you can opt out of the surveillance economy. In the physical world, that escape hatch is being welded shut. The supermarkets have established a monopoly not just on food, but on the terms of exchange.
There is a workaround, but it borders on spycraft. To avoid the tracking, I would need to set up a “burner” account with a fake name and a masked email address. Crucially, I would have to pay in cash every single time. If I were to slip up once and use my debit card, their systems could link that payment token to the burner account, retroactively tying every bag of pasta and pint of milk to my real identity.

Is this what privacy has become? A luxury good available only to those willing to act like fugitives in the pasta aisle?
There is a profound inequality here. We often talk about the “poverty premium,” where being poor costs more (prepayment meters, high-interest loans). We are now seeing the emergence of a “privacy premium.” If you can afford to pay the non-member price, you get to keep your data. If you are struggling with the cost of living, you are forced to sell your privacy just to afford the basics.
My attempt to build a communal alternative failed because the system is rigged against anonymity. But it was a useful failure. It highlighted that the fight for data sovereignty is not just about servers and code. It is about the right to exist in public spaces without being tracked, indexed, and profiled.
I might have secured my digital home, but outside the front door, the company town is bigger than ever. And for now, it seems I have to choose between my principles and the price of olive oil.
I am stuck paying the premium for now. If any readers have found a viable solution, I would be very interested to read about it below or on my Keep in Touch page.
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