Earlier quoted context omitted.
yes. they will close your account if you receive money from dubious activities (sex and drugs usually). they will also close your account if you can't prove where the money is from. i had this issue myself in europe. a friend paid me back a hefty sum. my friend had issues proving where he got the money from. my account was swiftly closed.
What happens when an account is closed? Do they send you a check with the remainder of the money on the account, or do you lose everything?
you lose everything.