I also think/thought like that.

But if banks wanted, they could actually track the serial codes on the bills around. And since often cash is used in only 1 hop (so ATM -> you -> shop -> bank) they could know pretty well where you spent your money.

A quick reference: https://news.ycombinator.com/item?id=9948081

E.g. about China: "According to schedule, by late 2015, the serial number of every Rmb100 note withdrawn from banks by members of the public can be traced."

> But if banks wanted, they could actually track the serial codes on the bills around. And since often cash is used in only 1 hop (so ATM -> you -> shop -> bank) they could know pretty well where you spent your money.

That doesn't include how much you spend exactly. And it only works most of the time (what if my money gets used as change for another customer?).

Was waiting for this comment. I often ask myself, "Do I want any entity to have a copy of the exact dates and amounts of my entire daily consumer activity?". Whether anonymized or not there is a tremendous amount of knowledge that can be gleaned from non-itemized debit card ledgers.

Same here.

Also, been a couple of times in the situation where either the shop's card terminal was malfunctioning, or the bank had some issues, and the card payment was impossible. Without cash you'd be helpless in such a situation, whereas cash = power & independence.

And what of purchases made on websites?

As very few Germans even have credit cards, most Germans pay online (if they don’t use PayPal) via SEPA wire transfer or SEPA ELV. And even PayPal and Amazon support using SEPA ELV to pay for stuff.

Opt for money order, cheques?