Curbing The Populace

Somehow or other, bacteria and other tiny organisms manage to find food. Usually they just evolve the ability to eat whatever they can find in abundance. Hence, flesh-eating superbacteria... which will have billions and billions served!

Nature always finds a way.

Other Things That Might Suck

http://blog.wired.com/wiredscience/2007/10/superfat-black-.html

It would be pretty bad is this was actually the result of some galactically nearby civilization's superweapon... we'd be so boned by an alien invasion if they had tech like that.