What is the most dangerous ear piercing?
Anytime you go through cartilage you're asking for trouble. Cartilage has little to no blood supply and if it gets infected you're in a world of hurt. Stick to the fleshy parts, like the lobes.
One done against the receivers will.
The one when you let some crazy amateur do your ears in someone's basement using only a needle
I would think those gauges are dangerous when you stretch your earlobe out far enough like some people do.