When a giant bank gets a subpoena from the government, a very long and slow process begins. First, the banks cannot just say no. They must obey the law. This means they have to look through millions of digital files and emails written by their workers over many years.
To do this, the banks will hire teams of expensive lawyers who wear fancy suits. These lawyers will read every single email first. They want to see what is inside before they hand the papers over to the government. They will look for secrets and try to protect the bank. This takes a lot of time. It does not finish in a week. It will take many months, and perhaps even years, for all the papers to be gathered and read.
After the banks send the files, the government lawyers will read them. They will look for any messages where bank workers talked about tricking customers or hiding mistakes. If they find bad messages, they will use them to show the banks did wrong.
So, what should we expect next? We will not see a quick trial or anyone going to jail right away. Instead, there will be a quiet period where lawyers on both sides talk behind closed doors. They will argue about what the emails mean. The banks will try to convince the government that any mistakes were just accidents. The government will try to prove the banks knew what they were doing.