At least in most of the USA, the shopkeepers can defend their shops. It may not end well because there are so many entitlement leeches, but it will be a fight.
A picture says more than a thousand words:
Even in Kalifornia we are allowed to defend our shops with guns. The main problem in defending a shop or home is fire. You have to setup a screen or zone around the shops/homes and keep the rioters away. Looks like some British were employing those methods last night using swords, pots and pans.