I wonder if now the governments there consider people using cash "suspicious", just like the US gov considers not having a Facebook account suspicious, or how the Spanish Court in a recent case considered encrypting your e-mail end to end as "suspicious".

This is true in Norway.

Merchants are required by law to report cash purchases over a certain amount to the tax authorities.

The same has been true for cash withdraws from the bank over a certain amount, for decades. "Suspicious" isn't quite the right word, as there are plenty of legitimate reasons. But the cost (reviewing a small number of large withdraws) vs. probability of detection is good.

The scary part is how low that amount is. It's something like 1000 euro/day and 3000 euro/week. There's also a yearly value. It's been going down over time (by a lot, used to be 5000 euro/day only when the euro was introduced).

Why do you believe "the US gov" (and which branch and agency, specifically) considers not having a Facebook account suspicious?

> We seem to presume that anyone "off the books" is up to no good.

Off the books is no good by default. We have a phrase for it: tax evasion.

Not necesarily, you can be paid in cash by your employer and this is compltely legal.

Where I am from (Slovenia) it is completely illegal. In fact it is illegal for businesses to have cash expenses higher than a hundred euro or so. Very low by European standards, but all countries in EU have some sort of cash payment limit.

This is specifically to curb shadow economies and the grey market.

And the reason it's illegal to pay employees in cash is that the government needs a way of tracking "automatic" social security and tax payments. Where automatic means the employer pays them as the part of the paycheck that doesn't go to the employee.

In the UK it's not illegal. You can pay them in cash in hand. Most builders and workmen that do work in your homes are paid cash in hand when they come round, this is common. They just need to declare it with the correct authorities themself.

Yes, we do that here too. But you aren't their employee, you are their client.

Important difference.

Sorry, you can still be paid cash in hand from most employers. Although most wont offer it. Pubs, bars, nightclubs lots of places you can be paid cash in hand. Just a lot of places choose not to do it as it's easier to manager there cash flows.

That's not off the books then.