All this talk of "troops firing on Americans". LOL.
You all are picturing troops showing up at the local park on a Sundy afternoon, shootin up the church watermelon and quilting social.
Instead, picture hundreds of desperate people (Americans) clamoring for food or supplies for their family, armed to the teeth most likely, fighting over scraps and supplies, running the streets in gangs, in full blown survival mode. In a SHTF scenario, more than a couple people here may well go into panic mode and do despicable things in an effort to claim theirs.
What would troops do if faced with burning cars, molotov cocktails, armed Americans running the streets in big groups?
When asking this question, do you picture troops would just be randomly walking around Mayberry USA shooting passerby's as they were walking their dog or shopping for shoes?
