They need a warrant by law in most cases but ICE seems to be requesting this data without much to back it up. The standard approach is to challenge it and keep records of the interaction.
>You have no authority over the bank.
And ICE doesn't have authority over Motel 6 without a warrant.
That’s under the assumption that ICE isn’t lying and intimidating. I find it completely believable they would use illegal and underhand tricks.
Your legal duty to your customer doesn't end wherein this duty is inconvenient.