Surprisingly, I was still able to get the left cylinder to fire and I got home to replace the plug. I was pretty lucky they didn't break any fins or strip the plug from the head or get pieces of anything into the cylinder.
I was stumped as to why they'd want it, until I started google searching "crackheads" and "spark plugs" and found that if you throw a piece of porcelain at a car window, it just shatters instantly. Neat trick.
