I believe, there are two reasons for the recurrence of such incidents. One, the officials know they cannot be sued at any court of law. Secondly, we, the people, as individuals, care only about our own plant and say "hell with the garden." I am sure while this incident took place, some people must have gathered around, staying at a distance always. What would keep a ruffian from acting like this then? The problem is that of complete absence of check and balance of any kind.
We, the people, as individuals, must take care of the garden and say "hell with my own plant". We must rest assured that, when the garden is flourishing, out plant cannot remain grey.