Let's review the applicable rules:
In Florida, deadly force may be used to protect oneself from death or serious bodily injury, or to prevent the imminent commission of a forcible felony.
Forcible felony, according to 776.08, includes arson, aggravated assault, and the unlawful throwing, placing, or discharging a destructive device or bomb, and any other felony that involves the use or threat of force.
Throwing a Molotov cocktail is arson, which is a forcible felony.
A Molotov cocktail is also considered to be a destructive device under 790.001.Throwing one is a forcible felony
Participating in a riot whereby the participants are forcibly and violently attempting to destroy any building is a forcible felony under 870.03.
This means that anyone rioting, throwing, or preparing to throw Molotov cocktails may be lawfully engaged with lethal force to prevent the imminent commission of these forcible felonies. The riot of arson need not be directed at you, as you would be employing lethal force to prevent the imminent commission of a forcible felony.
However, under Florida law, you are not allowed to possess firearms in any public place, once a state of emergency has been declared. (870.44)
What does this mean? If there is a riot in your area, stay home, and make sure that you are ready to be there for a few days.