Recognizing Hyper-Vigilance.

The lizard brain reacts, it does not think critically, it does not think at all, it does not assess or try to make sense of anything... In other words, once activated, it cannot be reasoned with.
In hyper panic mode this is the area of primary operation and, in hyper panic, overrides everything else with the ‘thinking’ side, our conscious, rational, and reasonable side constantly playing second fiddle catch-up as it justifies all actions of the lizard brain after the fact.

It helps to know what we might be dealing with, both in ourselves AND in everyone around us. The panic buying with no seeming rhyme or reason behind the items bought and hoarded; signs the lizard brain is in a hyper-vigilant State (and a bit rusty with no experience due to psychic atrophy, which can make it all the more dangerous, albeit not necessarily more unpredictable).
A person operating in a constant hyper-vigilant state will justify anything so long as their survival is guaranteed, even accepting less freedom, more tyranny, and justifying acceptance of any information from sources perceived to be most conducive to survival (due to prior perceived status) without question.
These sources, and their agents, assuming a high status point in a perceived dominance hierarchy with the lizard brain forcing the individual into a subservient role.

This explains what has already been happening, but the trajectory is not good over an extended period of time as things further erode and survival is constantly in question.
People will often be shocked by what they are capable of doing, furthermore, what others are capable of and willing to do to them... Mob Mentality is one manifestation of a collective lizard brain, tribal mindsets are another.
People, desperate, breaking windows, kicking in doors, invading homes to get at the goods within (and likely much more, to the horror of the victims unprepared).
Attacks in stores and store parking lots are only the tip of the iceberg if things continue down this road and fear porn is spread around continuously like candy.
‘Worry about this,’ and ‘why aren’t you worried about that?’ Memes literally State by end of the world messages in the midst of it all, stuff we would normally find ridiculous. Amidst all this, individuals not necessarily operating from honest places of concern seeming to stoke the fire and fan the flames because they want to make a statement at the expense of everyone else who are genuinely afraid.
(I had to block two people in such a category a couple days ago because of statements in public... And contradictory statements in private from one - this is not a political issue and to assume it is whilst approaching it like that is dangerous considering the level of panic).

Knowing is more than half the battle. Remaining aware, taking the hyper-vigilance down a few notches, being mindful in all situations, of yourself and others, this does go a long way. When the lizard brain enters go time, however, all bets are off.
Others will try to take what you have, and more, you cannot approach that in the same mindset you normally would, can you defend what you have? Where are you willing to go? It is not a pretty picture and there is time to change some of it, at least with those around you, your neighbors, friends, and family, strength in numbers is a good deterrent, but the picture still sucks.

Sticking together and staying positive is the optimal plan of action, but being aware of the worst within will prepare for the worst as it comes from the outside to tear you apart and take everything that is yours.

Gloom and doom? No. Just realism should things go this way for an extended period of time. Get yourself out of your state of sheer panic and recognize when you are dealing with the lizard brain in other people.