There's no such thing as financial privacy when you, by virtue of being a citizen of a country, consent to be taxed on income and investment. Your financial actions may not be necessarily public to your fellow citizens but they absolutely and without possible argument must be to your tax assessor, and this exists to hide transactions from them. Of course it's illegal.
You can revoke that consent, as it is possible to become a citizen of no country, but I wouldn't recommend it.
You can revoke that consent, as it is possible to become a citizen of no country, but I wouldn't recommend it.