Honestly it's absurd that that we have two distinct numbers (account and routing) but you always use both, they don't change, and they are good for both deposits and withdrawals. It would be so easy to only require an account number for deposits and to have a unique routing number for each withdrawal. Maybe for convenience you have some fraction of your assigned routing numbers be good for repeat withdrawals but only for the amount and frequency specified for the first instance. Thus you can hand out your bank account number to anyone without concern, and they can give you money easily, but only those who you legitimately desire to pay can take money from you and their opportunity for abuse is limited, and all the infrastructure remains relatively unchanged.