The Omission of Transmission

There's an issue I see a lot when certain scientific topics come up. I don't think it can properly be termed a logical fallacy, though by brute definition it certainly qualifies. I think a more appropriate expression would be conviction tempered with ignorance. At any rate, the issue is as follows:

Someone reads/sees a piece of media about some technology/substance. The video makes a claim on what could be done with this technology, often with the implicit, "If only those dang capitalists and politicians weren't so stubborn and greedy!" Our enthusiast, who in all honesty has society's best interests at heart, now forms an emotional connection with the assertion and becomes belligerent when confronted with opposing views.

Two examples: power and cancer cures. I see media all the time claiming things to the tune of, a solar farm yea big in thus a location could provide the world's energy needs. Maybe it's algae. Maybe it's solar panels in orbit. Maybe it's a crop of wind turbines. I also see media, or just people, shouting that thus and such a substance kills cancer, but the government keeps it illegal.

Where our sanguine enthusiasts err is in transmission. They fail to understand how massive, long distance power works. If you were to try and power the world from one solar farm in the Sahara, all you would accomplish is heating a lot of wire. They fail to grasp that simply because something kills cancer doesn't mean that it can do so in vivo without compromising the well-being of the host. Fire kills cancer. Toss a hunk of cancer into a vat of gasoline, light it up, then try and tell me the cancer's still alive after everything's burned down.

The unfortunate thing, I've found, is that though most of these people are well-meaning, they won't let go of their convictions once presented with counter evidence, because they've welded themselves to their convictions with emotion. The trick is to disillusion them in a friendly manner so that they won't hate you when they don't believe you. An even greater trick is to disillusion yourself regardless of the manner.