Dogpiling, dog-piling or simply a piling-on is a form of online harassment or online abuse characterized by having groups of harassers target the same victim. Examples of online abuse include flaming, doxing, impersonation, and public shaming. Dog-pilers often focus on harassing, exposing, or punishing a target for an opinion that the group does not agree with, or just simply for the sake of being a bully and targeting a victim. Participants use criticism and/or insults to target a single person. In some definitions, it also includes sending private messages.