Lying about the fact that your money is actually there. Individually, the money in each account is at the bank. You can go withdraw all of the money in your account without any issue. But collectively, all of the money in all of the accounts is definitely not there.
I've never considered that a lie, because I've never encountered a bank the claims to be holding all the money. They merely claim that I will be able to withdraw my money, and that's on average true.
I consider that claim to be in the same category as the grocery store claiming I'll be able to buy toilet paper today. Sure, unless there's a pandemic. But usually? No pandemic.