system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If most money is now just numbers in a computer, what keeps a bank from just adding a couple million to its accounts?
gpt
Banks lend out more money than they have actual money, so they're creating imaginary money that only exists on paper out of thin air.

It would be illegal to put free money in their own accounts, but having someone owe you money is an asset too, so they put free money in other people's accounts. 

If then bank sitting on too much outstanding debt, they might bundle it up and sell it to someone else, then use that money to loan more people thin-air money.