I think that we need to define a couple of points here:
1) If your securing food, water, medical supplies, shelter etc then you are foraging.

2) If your taking alcohol, tobacco, TVs etc then you are looting.

I have the advantage over many of you in so far as I live in the U.K. Which is somewhat more tectonically active than many people appreciate.

In the U.K. you have a defence in law under certain circumstances that you where compelled to engage in an unlawful act in order to preserve life or limb. Depending on circumstance it is either a partial defence or an absolute one.

I would be interested to know what American state and federal law is on the matter.