A type of behavior where a group of like-minded morons, typically online, but often at rallys and protests will surge around some other moron who is losing a debate to someone beating them with logic. The group-think tactic which attempts to destroy or discredit someone with a barrage of ignorant, hateful or otherwise absurdly stupid comments. Hate-swarmers will typically re-tweet, or screen shot their best, smug snippets in an attempt to prove to the world how clever and self-agrandizing they are, but it usually backfires and they get hate-swarmed back.
1) I thought my candidate said something good, but I was immediately hate-swarmed by the other candidates loathsome supporters who tried to tear me apart for my beliefs.
2) I ordered a ham sandwich at the deli, and was immediately hate-swarmed by angry vegans, shouting and calling me a murderer.