A small unit in a neighborhood could be workable. Park it on a centrally located fenced property.

I seriously doubt that any part of the government, federal or local, is going to confiscate the contents unless they're REALLY desperate for a bunch of buckets. Too little contents for the effort.

The main problem with those intermodals is that they are metal and they sweat badly with temperature changes. Using an adhesive to tack some sheets of foam insulation on the walls and ceiling might help. Doing this, people could include larger plastic totes with more supplies. A 20' unit has over 1,000 cubic feet, which would be over a cubic yard per family for a neighborhood group of 30. That's quite a bit of storage room, tightly packed, for survival gear.

Interesting concept.

Sue