how easily do Lithium Polymer (LiPo) batteries catch fire? 1. physical damage

DANGER - DO NOT TRY AT HOME - SAFETY FIRST
A safety video showing just how easily these common Lithium Polymer batteries catch fire and explode. I do this so you don't have to.
These batteries are in phones, drones, cameras, laptops etc etc they are the standard small grey packs - it becomes quickly obvious why airlines and postoffices don't like them (the fire can burn through aluminium tubes)....these had puffed so although showing 4.2V carried little actual current but as can be seen it's more than enough to set fire to anything in your house after burning you and filling your lungs with toxic smoke.
This was a small 3S 2000mAh drone battery pack - the first i destroyed as a test, the 2nd just took a couple of dull blows with the hammer and the 3rd was due to the intense heat from the 2nd (they could still boil water 3 mins afterwards).

As we move into the Electron Age be very careful, 1 electron does little on its own but when you move loads of them they can deliver huge amounts of power.