Complex sentence: Gamergate supporters subjected other victims to similar harassment, doxing, and death threats, and those who came to the victims' defense were ridiculed as "white knights", or "social justice warriors" (SJW).
Split into simpler sentences: Gamergate supporters subjected other victims to similar harassment, doxing, and death threats. Those who came to their defense were ridiculed by Gamergate supporters as "white knights", or "social justice warriors" (SJW).