I had a checking account with CityBank during my stay in the US in 2007. A lot of US-based online stores wanted US-issued card only (the same goes for UK stores, same attitude towards foreign cards), so I had to physically withdraw money from my Ukrainian card and deposit it to my US account (other options were not available at that time).
So once I found out I can do the deposits without bank teller via the ATM I decided to try it immediately.
Here's my dialog with the machine:
What do you want to do?
How much do you want to deposit?
(Huh? That does not look right, you should check how much I have deposited. Okay, let's test) $200
Insert bills or envelope
(Excuse me? An envelope? How will the ATM check the bills are genuine? Bills or envelope... ok, I will go with the bills. I insert the stack of bills into the machine hoping there's some sort of feeder and verification system in place and notice the bills simply dropped somewhere inside the machine, oops)
Thank you for banking with CitiBank
This happened after working hours, so I decided not to continue stuffing the ATM with my money for the time being and see whether something goes wrong.
At home I checked CitiBank onine banking system and found that I had a successfull +$200 deposit.
The next day I went to CircuitCity and purchased some things using the card, when I returned home in the evening I found out that I had -$140 balance on a debit account.
Something went wrong.
The next day I went to CitiBank branch, spent half an hour with my account manager explaining what I did, she asked around and one teller confirmed that yeah, they had $200 unaccounted in the ATM because some idiot (my word, not theirs) decided it was a good idea to shove the money into the deposit slot. Overdraft was dropped, I learned a valuable lesson and used an envelope next time.
In 2011 Citibank started switching to ATMs that count and verify the bills and no longer require these weird envelopes.