After the events of Chaos where Optimus Prime defeated D-Void, Cybertron was "reborn" and a signal was sent out into deep space. The NAILs; a group of non-combatant Cybertronians, received the signal and returned to Cybertron. Expecting a paradise the NAILs instead found a wasteland. They demanded that the Autobots leave the planet to them, for ruining it with "their" war.
A riot ensued and the Autobots used their Decepticon prisoners as crowd control. The riot ended when Optimus addressed the crowd, announcing his intention to go into voluntary exile, in exchange the Autobots would be allowed to stay on Cybertron.