Blackmail

Blackmail is the act of coercion using threats to reveal compromising or private information about a person unless certain demands are met. Within the Wizarding World, blackmail is utilized by various individuals for a wide range of purposes, from schoolyard bullying to high-stakes political maneuvering and furthering the aims of the Dark Arts. It is a tool not exclusive to Dark Wizards, as demonstrated by its use by characters like Hermione Granger for what she perceived as a greater good. The threats involved can range from revealing embarrassing secrets to exposing illegal activities or threatening physical harm by third parties.

Throughout the series, several key instances of blackmail serve as important plot devices, revealing character motivations and driving the narrative forward.

• Draco Malfoy vs. Harry Potter and Friends: In their first year, Draco Malfoy discovers that Harry Potter, Ron Weasley, and Hermione Granger are helping Hagrid illegally raise a Norwegian Ridgeback dragon, Norbert. He attempts to blackmail Harry by threatening to expose them, hoping to get them into serious trouble. His attempt fails, and he is caught out of bed along with them, receiving detention as well.
• Lucius Malfoy vs. The Hogwarts Governors: In 1993, Lucius Malfoy successfully blackmails the other eleven Hogwarts school governors. He threatens to expose embarrassing secrets or, in some cases, curse their families if they do not sign an order for the suspension of Albus Dumbledore as Headmaster following the attacks by the Basilisk. The governors later admit to Dumbledore that they were threatened into signing.
• Hermione Granger vs. Rita Skeeter: This is one of the most significant and long-running examples of blackmail in the series. At the end of the Triwizard Tournament, Hermione Granger discovers that journalist Rita Skeeter is an unregistered Animagus (a beetle), a secret she has used to spy for her sensationalist articles. Hermione traps Rita in a magically-sealed jar and blackmails her, demanding that she stop writing her libelous stories for a full year. In the following school year, Hermione leverages this same threat to force Rita to write an honest, in-depth interview with Harry Potter about Lord Voldemort's return, which is then published in The Quibbler.
• Draco Malfoy vs. Borgin: During his sixth year, Draco Malfoy is tasked by Lord Voldemort with a mission inside Hogwarts. To accomplish this, he coerces Borgin, the owner of Borgin and Burkes, into helping him repair a Vanishing Cabinet. Draco blackmails Borgin by threatening to bring the violent Werewolf Fenrir Greyback to his shop, implying Greyback would attack him or his family.
• Mundungus Fletcher vs. Kreacher: After the death of Sirius Black, Mundungus Fletcher loots Number Twelve, Grimmauld Place of its valuables. When the house-elf Kreacher tries to stop him from stealing Slytherin's Locket, Mundungus blackmails the elf. He threatens to report Kreacher to the Ministry of Magic for disobeying a member of the Order of the Phoenix, knowing that such an act would result in the house-elf being forcibly removed from the home he was bound to protect.
• Rita Skeeter vs. Elphias Doge: While writing her slanderous biography, The Life and Lies of Albus Dumbledore, Rita Skeeter interviews Elphias Doge, a staunch defender of Dumbledore's reputation. In an interview with The Daily Prophet, Rita implies that she silenced Doge's protests by threatening to reveal a “nasty little secret” from his youth, effectively blackmailing him into compliance.