No, seizure is a legal concept. There's no physical bank account the feds can somehow move into a locked room. The bank retains the technical ability to let you

No, seizure is a legal concept. There's no physical bank account the feds can somehow move into a locked room. The bank retains the technical ability to let you use your seized bank account anyway. It's just a bad idea because it's illegal, and if the bank did that, somebody would get into a lot of trouble.