An Armed Revolt is a Powerplay-related System Signal Source specific to Yuri Grom. It is similar to a Conflict Zone, but contains ships aligned to a Power battling against a system's defense forces. At these sites, the Power is trying to prepare the system for its expansion there by inspiring a popular revolt. When aligned to Yuri Grom, pilots will receive 10 Powerplay (bonds) per ship killed at Armed Revolts.
To locate a system with active Armed Revolts, check the "Expansion" tab of Yuri Grom in the Galactic Powers menu.