Some ATMs allow depositing money on an account, without prompting for a PIN number. This is probably a convenience to users, but I believe it is also a basic breach in security.
The tradeoff between convenience and security is quite hard (e.g. unlocking smartphones with fingertip scanning or NFC payments), but I can see scenarios where a password is desirable on deposit. The main scenario is to deposit "dirty" money on a stolen-card account to shame the owner (false bribery, false laundering, etc.).
I wonder why some ATMs do not require the PIN on deposit, except the user experience reason.