euro in your account without official documents where it is from.
You can’t send money outside the country on weekends because there is nobody to check if this is legit.
The banks would gladly take whatever you give them.
A other example.
Until recently we (Swiss) had a “bank secret”, no one could ask anything about a persons accounts if they didn’t ask about a certain transfer from or to a certain account validated by a judge. And then came the USA. Since then every single movement on an account of a foreigner must be copied to his country’s government: automatic information exchange!