Actually it's very often easier to charge an EV from your own solar, wind or microhydro than it is to prepare your own petrochemicals.
I remember one hurricane from high school where we were out of power for 2 weeks. We were siphoning gas from anywhere we could get it and storing it in a boat with a 1,000-gallon tank which started about half full. We had enough fuel to drive across the country and back if we had wanted to without any issues. I was driving around like everything was normal during that period. Seeing friends and family daily picking up water from the national guard, etc.
With EV's all you have to do is flip off the power and they'll all be dead in days at most with a couple hundred-mile range maximum. I'll take petrochemicals in a disaster any day of the week.
Now if we're talking no power for months that's a whole different situation and solar panels are the least of your concern. You're moving more into the realm of how many bullets do you have at that point.
No doubt that was to block protests
In the real world though protesters don't use cars - they instead block roads to prevent cars from driving on them.
No they wouldn't. Basically every EV is Internet-connected, so they just need to tell the manufacturers to remotely disable the cars.