This probably isn’t what the OP means by it, but I’ve encountered a number of trolls who justified, or rationalized, their trolling by claiming to act as a counter to groupthink, or as predators in the ecosystem of ideas, or as some kind of Socratic gadfly. It’s up to you how much you want to trust those claims, but they are arguably altruistic and do seem consistent with the definition you offer.
This probably isn’t what the OP means by it, but I’ve encountered a number of trolls who justified, or rationalized, their trolling by claiming to act as a counter to groupthink, or as predators in the ecosystem of ideas, or as some kind of Socratic gadfly. It’s up to you how much you want to trust those claims, but they are arguably altruistic and do seem consistent with the definition you offer.