If people are hoarding and stockpiling, at least part of the response needs to be to look at the motivation these people have to stockpile and address that motivation. A hoarding problem is probably a valuable signal of some deep societal issue of distribution that needs resolved.

The vast majority of scarcity we face in this capitalist-controlled world is manufactured, so I wouldn't think actual scarcity would often be an issue, but if hypothetically it was and someone was stockpiling more than they could use of some basic need like food allowing others to starve, I'd say the starving taking the surplus (the portion the stockpiler can't use) by force would be justice.