> proliferation of technologies that give ever smaller numbers of people with smaller amounts resources the ability to impact billions of people

did you mean greater number of people with less resources?

EDIT: thanks to others that point out how you can interpret this differently, which I think is: "it is now easier for smaller teams with fewer resources" rather than my original interpretation of "power is now concentrated so that fewer people can do this than before"

No, I think they mean that it used to take a giant lab full of specialists with lots of funding to do lots of damage before.

Now, the worry is a lone nut in a basement with no money could pull off an act of bio terrorism.

I had the same reaction, but I think they meant fewer as in "requires less consensus-building to wield meaningful power." Used to have to convince lots of people to go to war in order to kill a couple million people. Fast approaching a one- or two-man weekend project.

Fewer as in the size of an individual group, even though the total number of people who could find themselves in such a group is greater.