Complex sentence: Mirroring Mississippi's similarly named authority, the commission acted as a state intelligence agency to spy on Alabama citizens suspected of sympathizing with the Civil Rights movement and participated in economic boycotts, such as firing from jobs and eviction from rentals, that affected many activists.
Split into simpler sentences: Mirroring Mississippi's similarly named authority, the commission acted as a state intelligence agency to spy on Alabama citizens suspected of sympathizing with the Civil Rights movement. It kept lists of suspected activists and participated in economic boycotts, such as firing from jobs and eviction from rentals, that affected many activists.