You can't hear them coming. They're as silent as cats, streaming suddenly into view with no engine noise and no fair warning. They're cruising down the street like a ghost fleet. They don't need food or gas or fuel of any kind. Don't worry, though, they're generally harmless as long as you don't make any sudden moves. Just let them slide on by. Wear this tee to spread the word that the silent, electric beasts are prowling around.