it's a way to free the judiciary of time consuming cases. before someone with a lot of money that wanted to harass some poor bastard would take him to court on any frivolous charge and crunch him on the weight of a legal defense. That was fine and worked just fine. but it was taking too much time of the judges. So they came up with the cease and desist letter. it works the same, the rich can continue to harass the poor, but no judge have any extra work. win-win!
