This is certainly a unique story I found on Bruce Scheier’s blog…
http://www.guardian.co.uk/world/2009/jul/12/south-africa-cash-machine-pepper-spray
In South Africa they are testing ATMs that squirt pepper spray into the face of anybody deemed to be tampering with the card slot…
The technology uses cameras to detect people tampering with the card slots. Another machine then ejects pepper spray to stun the culprit while police response teams race to the scene.
Here is the issue though image recognition isn’t 100%. In fact it’s very spotty at best. Hence I’m guessing there will be a lot of false positives here. Either that or the machines will be set towards the safe side and not actually spray the people that are tampering with the ATM.
Either way this sounds like an interesting idea with a flawed implementation.
Source: http://www.schneier.com/blog/archives/2009/07/pepper_sprayequ.html