Everyone Under A.L.I.E.'s Control Is Free . . . Sort Of
At the end of the season three finale, Clarke reaches A.L.I.E.'s kill switch at the heart of the City of Light and shuts her down. By this point, A.L.I.E. had convinced (and often blackmailed) many Grounders and Arkadians alike to swallow a "chip" that would let them into a virtual reality where there is no pain or fear — or independent thought. These people would do whatever A.L.I.E. asked, no matter how horrifying, in order to turn more and more people into brainwashed slaves. With A.L.I.E gone, everyone who took the chip is free. While that's a good thing, it also means they have to face the reality of what they did under A.L.I.E.'s control.