I'm not sure if it's griefing, me and my friend once built a fake city in minecraft, with houses to purchases, farms, stores and stuff like that. I hired some security guards and I was the mayor, but we also built a secret area under the whole city which nobody else knew about, and there was a curfew where everyone had to stay in their houses for the night. Pretty much everyone complied. Eventually the whole server were residents at my town, so during the lockdown we secretly rigged the town with TNT directly under the citizen's homes when they were inside, blew up the whole block, leaving no survivors, and picked up all their hard earned items.
Was a fun night.