how would the united states government find out if an offshore bank is withholding information for someone who is only a legal permanent resident? lets say that banking officials at an offshore bank account use some kind of secret method to avoid the obligation of reporting these accounts to FATCA. how would uncle sam find out if this was taking place and the bank was actually doing this? would they investigate and if so, how? or would they shut down the bank and freeze assets? how would uncle sam find out if a bank was doing this? can a financial offshore banking expert please tell me what the american government would do if this was taking place but couldnt prove it or had any evidence? thank you.