I have read many news that someone will mismanage people's money. I read one about a university student some years ago that gambled with the money contributed by his course mates. The main reason that is causing the money mismanagement is either trading or gambling, but I read more about gambling online. Some can be because of other reasons.
Those things seem to be very common this days were people use the money they put under there care to gamble and at the end they lost the money and funny enough is only gambling that can make someone behave that way, however I witness similar case of someone who was a Treasurer and was holding a huge money for there organization but based on what his friends told him that he has a very sure game that has 100% chance of playing so the guy decided to be greedy and use all the money that was given to him and use it to gamble and at the end he lost everything and he couldn't withstand the trauma he fainted.
So for me I believe one of the reasons why those things happen to them is because of greedy of trying to become rich overnight without knowing that there is no easy way to success so the moment most of them realized that the better for them because I'm still surprised how someone with his right mind will use a money that's being given to him by a group or organization to gamble when he knows that nothing is certain in terms of gambling and there is a higher chance of losing everything on the process.