One simple example is the requirement of keeping a minimum balance to maintain an active bank account. In my country, if I want to keep an active savings bank account, I will have to maintain a minimum balance of 10,000 INR. If I fail to maintain that amount, bank will deduct charge of 150 INR for each day and that money will be recovered from your bank account.
Lets assume, your account balance is 9,500 INR on 1st November. Bank will deduct 150 INR non-maintenance change from that same account. So on 2nd November, your balance will become 9,350 INR.
So if you want to refill your bank account on 2nd november, you will have to add 650 INR to your bank account! That's an organized loot!! It's your money but bank will not allow you to withdraw it even in case of an emergency!! If you do, you will have to pay charges for withdrawing your own money!
I have lot of other examples available because I used to work in a closely related sector. That's just a teaser for you!
In order for our account to be active in bank, we should have always a balance. That is also a protocol to my country. I want to have ATM card someday because I want to withdraw my earnings in cryptocurrency using bank. However, if there could be a cashless bank and accept cryptocurrency, I will never get a card.