Protesters were attacked by government forces over the protest of Prime Minister Recep Tayyip and his instituting of authoritarian Islamist rule. For the past half century, Turkey has been open to all forms of religion. Protesters feel as though the Prime Minister is becoming a Sultan or a form of Dictator and they don't like it. They feel that under Islamist rule their freedoms will be taken away from them.
The Prime Minister has been good for Turkey on the global scale but at home he is looked upon very badly. Unfortunately, this is just another country going through a period of forced religious rule and since they have felt the spirit of freedom are not taking it very well. Sure hope this is not another civil war in this area of the world.