Or maybe just pull the cable leading into it

found on Reddit

Sure you COULD follow the directions on the sign, but that would risk personal injury and it would take longer which would give the attackers more time. It's easier to defend those machines if you can cut off the attack at a single point.

At least it controls some kinds of access

from here (image source)

I hope they never have to replace any hardware. I'm not sure how they'd get it out.

Deny All

found on Sizzle