I have taken back my card and walked away forgetting to take my cash on two occasions when using such systems. The stupiditity of users knows no bounds. There'

I have taken back my card and walked away forgetting to take my cash on two occasions when using such systems. The stupiditity of users knows no bounds. There's a definite trade-off here: on the one hand, people are less likely to forget to take their cash; on the other hand, people who find a forgotten card in an ATM are unlikely to abuse it, but if they find cash, they'll probably just pocket it.