It's unbelievable, what some people will do. This is about bottle bombs and is confirmed by Snopes. The Snopes link has a short video demonstrating the bomb's destructive potential.
If you see something like this, call the police; DO NOT PICK IT UP. Don't pick up any plastic bottles that may be laying in your yards or in the gutter, etc.
Bottle bombs are made with:
1. A ----- [here was included a list of ingredients that seemed a little too much like "instructions," which I removed so certain teenage boys of my acquaintance wouldn't decide to experiment and lose yet more fingers]
2. A little -----
3. A little -----
4. A small -----
5. Disturb it by moving it; and BOOM!!
6. No fingers left and other serious effects to your face, eyes, etc..
People are finding these bombs in mailboxes and in their yards, just waiting for you to pick it up intending to put it in the trash. But you'll never make it. It takes about thirty seconds to blow up after you move the thing.