millions of american families rely on the bank hsbc for everything from checking accounts to mortgages. But today, the bank agreed to pay a record amount to the united states government, ly $2 billion. The government says the bank did business with known drug lords, iran, even banks associated with al qaeda. As b reports, many are asking tonight, how did the bank manage to avoid criminal charges? Reporter: When the most ruthless of the mexican drug cartels wanted to hide their money, they went to hsbc. So did terror groups including hamas and al qaeda, along with iran and other countries on a u.S. Financial blacklist. All customers of a bank known well around the world. Hsbc, the world's local bank. Reporter: Today, u.S. Authorities said they were finally holding the british-based bank accountable. Hsbc had agreed to pay a record $1.92 billion dollars in fines and forfeitures. The largest forfeiture amount ever. Reporter: But give much less prominence in the announcement was a "deferred prosecution agreement" with hsbc, in effect meaning there will be no prosecution of the bank or its top executives, despite more than a decade of dealing with criminals and terrorists. This is a very just, very real and very powerful result. Reporter: You don't think the bank got off easy? No, and I don't think the bank thinks it got off easy. Reporter: But with $38 billion in profit over just the last two years alone, hsbc says it can easily afford its $1.92 billion fine. This is a signal to other banks that if you do this kind of stuff, you'll get a parking ticket, you'll pay the fine and you'll move on. Reporter: Since this summer when hsbc executives ducked questions from abc news, the bank's lawyers have argued that a successful prosecution of hsbc could have put the bank out of business in the u.S., Costing lots of jobs and disrupting financial markets. And in the end, u.S. Officials apparently agreed that in many ways, hsbc became simply too big to prosecute. The bank said today it is profoundly sorry, but for a small percentage of its yearly profits, hsbc has demonstrated how big banks can get away with crimes that would send others to prison for years and years. Brian ross, thank you. And we have another