A representative of car insurance companies made a random call to me today and ask about whether I am interested in buying their insurance in my next CI year. I was wondering who it was and couldn't really make it out as my Thai was insufficient to make formal conversation especially on the phone. So I called a friend who was standing about 5 steps away. They talked and this friend gestured so I knew it was some kind of a sales person calling. Why did we even bother to entertain such calls? And why me? My parents back home complained about the same thing. Too many who claimed themselves salesperson had made cell phone users' life miserable! How can we block such calls???