how did you jump from property damage and arson to speech? non sequitur much? financial damage absolutely can be violence, you can ruin someone's life if you take away their job by burning down the place they work at and it could lead to something horrific like them taking their own lives or not being able to pay for their medication or not be able to pay for their child's education, etc as a direct consequence of your act of destroying that place. destroying infrastructure people rely on to stay healthy/safe/economically stable/etc should be considered by civilized people as a violent attack on them, you cannot pretend that disrupting someone's livelihood is not at all related to attacking their liberty and/or life
a case where you can argue speech can be violence would be a verbal threat to hurt or kill someone, but that has nothing to do with what we're talking about, i don't know why you're bringing up speech, are you trying to say that destroying these cameras is a form of expressing freedom of speech? (not accusing you of this btw, just genuinely curious what you meant by that)