HSBC was the bank of money laundering of the mexican drug cartels. They also helped fund terrorist organisations like ISIS. They made it possible to at scale deal drugs in the US.
When they were caught doing this - they shrugged and said they'd try better. Then they got caught doing it again. And they said sorry.
Eventually the government was aiming to indict the bank. There would be criminal charges. People would go to jail.
It is a small fine compared with their conduct. They got 'let off' at the last minute arguably because of 'systemic risk'. Too big to fail. Again.
You can find all about it on Dirty Money on Netflix.