I like to react to tragedies posted on facebook with 'haha'
That seems crude, can you explain why?
I do it because I'm tired of people posting things like that on Facebook. Also, I think sad things are funny.
It can be annoying to watch people post tragic life events on Facebook, particularly if they seem like they're just trying to get sympathy. However, it's not appropriate to respond to such comments with laughter, otherwise you will seem callous. Either express sorrow or sympathy, or say nothing at all.
You only say that because you want to control my thoughts and I don't feel like being controlled.
I don't want to harm you at all. Real people get hurt or die, taking away from their tragedy is simply wrong. You can hide the story or ignore it and move on.