Yes, I have been to protests. Protests are not illegal in the Netherlands, you can go very far - especially if you protest for the 'right causes' - before you're stopped by the authorities. Protesters want to be seen protesting, that is what they do it for.

What you're describing is not protest but vandalism. The first is allowed, the second is not. That is what I said after all, that this rabble did not 'walk the path'.