I don't have any images to share, or hardware to be fabricated, or statistics to call upon. All I have is an idea.

The idea that, if you feel threatened or insecure whilst using an ATM, maybe from prying eyes or some dodgy looking person nearby - That you wish you could hit a discrete panic button to alert the authorities. But a panic button may be destroyed or tampered with in such a way as to be ineffective.

My idea is, instead of any type of dedicated panic button on the ATM machine, you could instead enter your PIN into the keypad backwards, or if you are forced to hand over your card and PIN number, you could give your attacker the PIN reversed so that if this new pin is entered into the machine, your bank account is then limited to just a small amount, say £50 and seems to act as normal, but the police are called upon immediately, and extra video and sound recordings are started in the surrounding area.

I'm sure this could be implemented into existing ATM machines.