What is wrong with these people?

I am incensed at a recent incident on our allotment site!
Between the hours of 11pm and 5am someone came onto the site and wreaked destruction just for the supposed fun of it.

Twenty plots in total were affected. For our part, they broke open our shed door and our next door neighbour's shed door was pulled clean off! Other neighbours had potatoes and carrots pulled up and cucumbers picked; particularly gut wrenching because of the hard work they put in.
Even more difficult to accept is the damage done to one or two people's chicken runs. Someone had their chickens let out.

Nothing was stolen...it was wanton destruction. Grrh!