For those arguing that machines are 'morally neutral', there are a few other things to consider:
As already mentioned here, the slogan 'Guns don't kill people, people kill people' is -- in my mind at least -- incredibly shallow. Obviously guns don't (themselves) kill people. Neither do cars themselves drive, planes themselves fly etc.. Even a 'self-driving' car remains dependent on whatever it was programmed to do by someone. In the end it is always us, as trivial as this may sound, who fly, drive or kill.
Yet what people don't except as equally trivial is that just as planes have an obvious tendency in their usage to fly -- and not, for example, swim -- and cars have an obvious tendency to be used for driving, guns have an obvious tendency to be used for killing. To compare, say, a gun to a knife, and to state that both can be used for killing, and thus if we were to outlaw guns we must also outlaw all kitchen knifes is really silly. A butter knife is much more likely to be used to prepare breakfast than a gun.
The important question to ask about machines, in my mind, is if machines themselves have a similar tendency. Once we use machines, the way we act, and how the world appears to us, seems to change dramatically.
A machine usually only works when it is automated, uses some resources and delivers some product. Thus my time, as someone using the machine, is structured by its rhythm. As soon as I buy a machine, such as a car or a computer, I also buy into its needs. I have to be able to buy petrol and electricity, which I am most likely to afford if I have a regular income. Suddenly foreign policy decisions, which have an effect on the oil price, also effect me personally, and I can be swayed politically to vote in my own oil-self-interest.
My employer may come to expect the same of me as of a machine, and I will be forced to consider my own time as a resource. Once everyone's time becomes a resource in production, the nature of interpersonal encounters changes dramatically. Even leisure isn't an exception to this rule, for it is also bought by my previous time-resources, and leisure time is always at the same time time, during which I could also be using my time reasons more efficiently.
If one can speak of an emerging technological rationality, constituted by our use of machines, then this form of thinking fundamentally alters our consciousness. Nature, time and humans become resources to exploit, problems only become worth solving when they are themselves technologically solvable etc..