Sadism

The post title is bit an irony to the content. Well 'am not talking about what the first thing that strikes the mind when anyone reads the word sadism ;) its an irony to sadism that i'm trying to convey.
There are people who extract pleasure by being brutal. I remember right in front of me a Willis Jeep being being reduced nothing more than molten chassis and ashes, this was way back in 1991 during the big cauvery water dispute. There were bunch of goons and primary school kids totally amused by their act of burning down the jeep in minutes.
I attach emotionally to living or non-living things., like people around me, my close friends, stuff like my pen/pencil, my clothes, last but not the least my bike and my car. Though these may look very trivial they all mean a lot to me and make my existence complete. When any of these are hurt or 'am about to lose them I'll be more hurt emotionally.
Yesterday I was a victim of one such boorish act. Night I had parked my car outside my house. When I woke up in the morning all I could see was that my car was blemished by dents and long scratches on the bonnet. It looked to me that stones being chalked and hurled along with sand being scraped all over the bonnet.
I don't understand what sort of humans would get into such acts of sadism. Why do people get so low to derive pleasure from such clodhopping acts and causing emotional pain to others ?