I am not crippled, but I am limping. It's ironic that it happened to me as I frequently take some time to collect them and remove them from the beach.
Every one knows what a 'sparkler' is, right? It is a length of wire that has 30 cm or so covered in some bright-burning compound. When the tip is lit, it will burn brightly and shoot sparks. It is mostly safe when in someone's hands (although I have been burned once or twice). The ones I find, twisted and mostly buried in the sand, are half-ass caltrops.