Now, ask yourself who built and maintained those FEMA camps over the course of all these years, in the dark of night, and it really gets scary.
Assuming they exist, the people who built and maintained them probably believed the "cover story" of them being for disaster relocation. Of course they might wonder why they weren't extensively used after Katrina, and other such events. I'm still skeptical about them myself. Oh I don't doubt there are various facilities out there, but how extensive they are, how defensible, and so forth I sort of doubt they are are real "camps", not that they could not be pressed into such service, as could the many closed or semi-closed military bases left over from the Cold War.