system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] What does one have to do to qualify as a dark wizard? Is starting an armed insurrection enough, or does one have to torture and suchlike as well? What if you're just really evil, but you don't start an insurrection?

Admittedly its probably pretty hard to have an armed insurrection without at least a little bit of torture going on (even if you have no hand in it, by nature of running an insurrection you're going to be employing people who really don't like the government, at least some of them are going to seek revenge).

Say you're a really powerful wizard, on par with Voldemort. What if you start an uprising based on, I don't know, goblin or house elf rights or taxes or something? You gather other wizards to your cause and train them as spies / assassins and have them infiltrate key institutions and parts of the government. Your plan is to purge the high echelons of society of anyone who opposes you, gain power, and reshape society to your vision. You're still trying to overthrow the government and radically alter the present social order, do you count as a dark wizard? Are you labeled as a dark wizard in newspapers and such? 

What if you start a murder/torture cult and make yourself really hard to kill / find using the usual methods, but you don't try to overthrow the government?
gpt
Dark Wizard is technically a legal status-- there's a list of some 237 spells, rituals, and other practices that qualify as "Dark Arts" as classified by the Wizengamot. Generally to qualify as a Dark Art, a spell has to have no other purpose than to cause physical or psychological harm, as distinct from hexes, jinxes and the like which may be inconveniencing or restraining, but not truly dangerous. A handful of other techniques, such as the Imperius Curse, the animation of Inferi, and the creation of Horcruxes also qualify, as does the breeding of certain dangerous creatures such as Basilisks. Apart from usually being expected to serve a sentence in Azkaban, or even being subjected to the Dementor's Kiss, Dark Wizards technically forfeit their legal right to practice magic of any kind or own a wand until an official pardon can be issued by the Minister for Magic themself, but the general response is "you lot just try making me and see what happens." Thus Aurors.

The Wizengamot are occasionally convened to update their list-- the most recent occasion was 1999, when the Severing Curse (aka *Sectumsempra*) was declared Dark Magic, and it was clarified that the Unforgivable Curses were still Dark Magic when used upon house-elves one has legal ownership of (this after a lengthy, impassioned bit of ~~nagging~~ advocacy from one Ms. Hermione Granger that lasted some 72 hours, a filibuster previously unheard of in the history of Wizarding government-- we normally only reserve that kind of patience for Quidditch matches.)