I've heard that some banks are too strict when your account suddenly gained a lot of money and they'll actually investigate how you did gained the amount.
for this point I have experienced it as a bitcoin user from 2015, and 2017 the balance in my account is quite surprising for bank workers because of its very suspicious value. at the same time the account was locked for several days to explain where I got the money. I say out loud, it's because of bitcoin and I earned it hard for the last 2 years.
On the other hand, perhaps the bank could not do anything because the accusations they made were nil.
And at least they've got an idea how some of their customers are gaining deposits if they ever say that it's from bitcoin investment.