There are a myriad of complaints against journalists and TV personalities, including satirist Bassem Youssef, for insulting Islamist President Mohammed Mursi. At least two journalists faced trials while others are still questioned.
But Douma is the first activist to be quickly referred to trial while in custody.
Prosecutor Mohammed el-Taneekhi said today that Douma's trial will begin on Sunday.
He was arrested Tuesday after a Muslim Brotherhood member complained that Douma called Mursi a "killer" and a "criminal," and blamed him for a violent security crackdown on protesters in the coastal city of Port Said that left 40 people dead.