You could argue that the most terrifying weapon of the post-modern era is the car bomb, delivering explosives anywhere, at any time, and hidden in plain sight. The only weapon that's possibly more piercing into the collective unconscious is drones, and the could very well combine the two.

If a Google Car is a car that delivers itself anywhere you want without the need for a driver, it is also a car that can deliver a bomb anywhere you want without the need for a driver. A Google Car bomb would be a self-propelled explosive. Driverless cars have every appearance of becoming road-going torpedoes, unknowingly driving themselves up to the gates of an embassy, the steps of a house of worship, the middle of a crowded market.

At least that's one possibility.

It's also conceivable that the Google Car could offer an end to the car bomb as we know it, and it all comes down to anonymity.

Part of what's so effective about car bombs is how anonymous they are. When the Sicilian Mafia broke out into war in the early 1960s, one of their key weapons was the car bomb, and every car bomb they used, they made out of an Alfa Romeo Giulietta. Explosives-filled Giuliettas blew up the homes of top mafia opponents, their allies, and the police. As Mike Davis describes in his 2007 book : A Brief History of the Car Bomb, "By the time the Costra Nostra civil war ended in 1964, the Sicilian population had learned to tremble at the very sight of a Giulietta."

The point is that car bombs are so effective because they are so well disguised: you, the Sicilian citizen, don't know if the Giulietta parked outside your house is packed with TNT or not. If, years later, you're living in Iraq, you don't know if the new SUV that pulled towards the markeplace is filled with old explosives from the Saddam years.

The Google Car might be an end to that kind of vehicular anonymity. Driverless cars all know where they are, where they've been, and where they're going. It 's not hard to imagine how you could track them. Conceivably, it would be easy to know if the driverless car parked outside your embassy had spent the last two days parked at the home of someone on your government watch list.

Of course, it will be years before driverless cars make their way into the hands of consumers, but it won't be long after that before they'll be used in "the poor man's air force." It never is.

Do you imagine that the Google Car poses a new kind of threat as a potential self-driving bomb, or will its new tech make it more easily tracked and more easily diffused?