Back in '87, a child suffered a fatal blow from a lawn dart, and her father lobbied Congress until they were declared illegal in 1989. And while I would never disparage a father's prerogative to exact revenge on a product that killed his child, it's important to note that the Bible has inadvertently caused far more deaths to children and adults than lawn darts, and we aren't yelling our heads off about that. However, the real downside to this situation is that people love "lawn darts," and if you can't buy them in a store, then you are either forced to purchase a used set on the internet (check out jarts.com) or build your own--increasing the danger potential three-fold. Here's an example.
Ingredients (per single Lawn Dart):
Model Rocket tube w/ fins attached
Threaded steel rod, 1 1/2" long
Threaded hose fitting (female)
12-gauge shotgun shell (optional)
Not that anyone should ever construct this, but if one were to imagine building such a nefarious device, here's how one might do so. Go to the hobby store and purchase a model rocket tube with the fins already attached (get the biggest fins possible!). Take the tube to the hardware store and find a threaded steel rod (around a foot-and-a-half long) that fits snugly inside, with about four inches sticking out of the rear (that's the hand-hold). To weight the dart in front, use a threaded hose fitting, screwing it down until there are roughly four inches exposed.
Now, this is already a deadly weapon. But just in case one is imagining something deadlier.
Get a 12-gauge shotgun shell. Unfold the end, and dump out the buckshot, and as much gunpowder as you feel comfortable with. Slip the empty shell onto the nose of your dart (the primer, or explosive metal part is on the tip), and tape it down tight. Move your target from the yard to the cement driveway, throw your dart, and run like hell in the opposite direction. Wait for explosion. Keep lawyer's name on speed dial.
Warning: Could cause death, dismemberment, blindness, brain damage, alcohol poisoning, serious burns, laryngitis (from screaming in pain), hefty legal fees, imprisonment, and. did I mention death?