So right now a lot of thieves stick up people with a gun/knife only to discover that the victim doesn't carry money at all ( i can say from experience 20+ times getting robbed, not a single dollar)
ATMs should allow you to deposit only wholesome ammount's of money, with a minimum of $50 and up by the multiples of 50's.
For example, you have $234 in your pocket, then you can only deposit $200 and $34 still stay in your pocket, but if you had $263 you can deposit $250 with $13 bucks in your pocket.
Why?
As i said above, this will allow the roleplaying of a pickpocket/thief, but in the same time there wont be much money lost from the players who get mugged.