We've watched this video several times and we're still not sure if it’s a matter of "vibration and resonant frequency" or " manipulative stupidonance" as suggested by some of the commentators on YouTube.
What we see here is a firefighter teaching some young lads how to break a car window with your finger instead of doing it the easy way with let's say a brick.
A young man wearing firefighter gloves then begins tapping the rear window of a car with his finger starting from the center and increasing the pressure diagonally until he reaches the corner.
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