Your use of "vandalize" is certainly too strong and calling people names generally shows a lack or argument. Yet (somewhat unexpectedly) you raise an interesting question, in your first two sentences: if you disagree with something (law/HN poll/etc) how far can you go before it becomes unacceptable? Your view would rule out all kinds of protests that interfere with the process that is being protested.

I think that is too wide a definition of unacceptable.