Getting zapped by a taser gun ain't no party, it ain't no disco, it ain't no foolin' around, but for some reason it looks like a party every time a taser is fired- because the cartridge is full of confetti.
So what is the point of all that colorful confetti packed inside the cartridge?
They're actually part of the AFID (anti-felon identification) system, and each one is printed with the taser gun's serial number, so the owner of the taser that has been fired can be identified.
There are dozens of AFID tags in each cartridge, which makes it virtually impossible for the firer (taserer?) to clean them all up from the scene and therefore discourages use of the weapon in a crime.
The Slow Mo Guys talked briefly about taser confetti in this video (around 1:25), which also shows what a taser impact on bare skin looks like.
It's definitely not a party, and definitely not for the squeamish.