Tools of Evil vs. Evil Tools

There's a long running conundrum about whether the side of Good can use the techniques of the side of Bad to achieve Good ends. Tolkein came out against this with the One Ring, which even Gandalf could not use for good. In Babylon 5, upon hearing that Sheridan was trying to think tactics like the Shadows, Delenn promptly dragged him off to a baptist whoop-it-up-church-service to get his soul back in order.

The tool I'm thinking of right now is the Mass Media and other weapons of mass distraction that have the effect of swaying or pacifying the masses. Can this tool be used for Good or is it inherently dehumanizing?

Other tools to consider (the badness I consider obvious, I suggest some redeeming factors): our modern 'precision' weapons (might there be a target deserving and a user worthy?), nuclear weapons (asteroid defense), the oil industry (mmm, plastics and petrochemicals (until we can grow it in corn kernels)), others?