I have heard of people doing that; what is really hilarious is when the box is rigged to explode when the porch pirate picks it up.
Hilarious, I agree! But I feel obligated to mention that rigging a package to explode could get you in serious legal trouble.
Rigging it so the dog poo gets mixed with water when the package is moved, and using packaging that takes about 5 minutes for a spilled liquid to leak out, is perfectly legal though ;)