The Senaspis Droid Ascendancy was a movement among the droid armies of Senaspis to rebel against the Galactic Protectorate and the Hutt Cartel, for which they were being mass-produced.
They approached the Mandalorian League and secretly signed a treaty, allowing the Mandalorians to invade Senaspis and use the conflict to their advantage against the Protectorate. It proved successful, and soon droids all over the Galaxy were second-guessing their masters and rebelling to join the movement, causing the Great Droid Panic. Citizens of the Protectorate could no longer fully trust their droids; they never knew when a droid might hear of the Ascendancy and murder them in their sleep.