AFAIK in Germany they can ask you to submit your banking history for tax purposes (for example they have doubts about your declaration), if you fail to submit it or refuse, they can go to the bank, but you are notified way before they go through the bank and if you comply with the request, they don't go to the bank at all.
Also the request must be authorized by the state tax office, it's not like every government employee can request and obtain the list of all of your transactions.
Also the request must be authorized by the state tax office, it's not like every government employee can request and obtain the list of all of your transactions.