Most of the protests could be considered as violent, due to the police shooting tear gas etc. into crowds of peaceful protest.

Protests where the protesters get violent would in my mind involve

A) Actual retaliation vs police, not just water bottles.

or

B) Destruction of government property.

or

C) Both.

Protests where it devolves into looting private property are not protests, they are riots -- that have at least partially been caused by people who _definitely_ do not agree with the protesters.

Edit: Just noticed your edit, no worries. I understood your intent fine.