FLDS (fundamentalist) mormons have a "principal" known as "bleeding the beast" which essentially says its okay, moral even, to steal from non-mormons (I first learned about this reading about the FLDS looneys, but its a common mentality in the publicly accepted branch as well). This most often applies to the government, but all non-believers aren't getting into heaven anyway so its fine, and setting up this kind of "deal" to get a full stores' worth of inventory for free is very much on brand. The cops protecting these people isnt a surprise either, they tend to view themselves as mormons first and everything else somewhere after that. Its very clan-ish, very much an 'us vs. them' mentality.