Andrew Slack finally read the Harry Potter series when he gave in to pressure from his students who were obsessed with Harry, the teenage wizard who uses magic, courage, and wit to confront dark forces and save the world.

Though the plot is fantastical, Slack, like millions before him, couldn't stop talking about the books. But then he realized that if Harry Potter were a real person, he wouldn't just stand around talking about himself. Harry Potter, Slack said, would "fight injustice in our world the way he fought injustice in his."

That's when Slack had the idea to mobilize Harry Potter fans around real-world problems—and it was easy for Slack to find parallels between the fictional stories and real-life issues.

In the Harry Potter series, author J.K. Rowling, who worked at Amnesty International prior to writing the books, wrote about inequality and even ethnic cleansing between pure-blood, half-blood, and muggle-born wizards, as well as non-magical people; werewolves forced to conceal their true identities from a culture that shames them; house elves that are enslaved and inherited down through generations; prisoners tortured in Azkaban, the wizard prison; and the use of consolidated media to control public opinion.

Most of all, says Slack, Rowling created a world that made "fun of normalcy as an aspiration" and believed that "the weapon we have is love."

Just as Hermione Granger started the activist Society for the Promotion of Elvish Welfare (SPEW) to try to end the slavery of house elves and Harry started Dumbledore's Army to fight Lord Voldemort, Slack started the Harry Potter Alliance—a movement of Harry Potter fans turning their deep love of the stories into real-world action in order to "fight injustice in our world."

Today, the HPA has 190 chapters in 35 U.S. states and eight countries and participation in the group spans all ages.

Slack and the HPA believe in the power of story to change the world and they believe that activism can be fun and lighthearted, even when the societal issues they're confronting are serious. Slack calls this method of making the world a better place through popular culture, "cultural acupuncture."

"Imagine people working to end global warming, racism, and genocide as energetically as they flock to movies," wrote Slack for the Huffington Post. "Imagine them walking out of Avatar with an organization that says, 'Here's how we can band together to protect Pandora by fighting the "Sky People" in the Coal Industry.'"

Here are eight issues the HPA has already taken on:

1. Labor rights

The Harry Potter Alliance took off when Slack and his friend Seth Soulstein, from their traveling comedy group, the Late Night Players, joined with the group Walmart Watch and created "Harry Potter and the Dark Lord Waldemart" YouTube videos.

The featured main character is a cloaked figure with a Walmart smiley face for a head, the evil Waldemart. The videos describe Walmart's unjust labor practices and how their low prices force local shops out of business.

Just as Lord Voldemort treats his servants poorly (for example, SPOILER ALERT!, he chops off Wormtail's hand and murders Professor Snape), Walmart, the world's largest private employer, treats its workers unfairly.

2. Fascism and genocide

The group rose in popularity when Slack and Soulstein combined efforts with Harry and the Potters, a rock band based on the books. Their first move was to mobilize already existing Harry Potter fan groups around ending genocide in Darfur.

This theme shows up in the books when, controlled by Voldemort and his Deatheaters, the Ministry of Magic establishes a policy of ethnic cleansing, believing people with impure or non-wizard blood have no worth.

The group worked with Sifa Nsengimana, a Rwandan human rights activist. With her help, in addition to creating a podcast, raising awareness, and sending letters to end genocide, the group established a library in Rwanda for children who were orphaned because of the genocide.

3. Disaster relief

With the help of the Wizard Rock community, HPA raised more than $123,000 in two weeks for Partners In Health following the 2010 earthquake in Haiti. With this money, PIH was able to fly five planes full of emergency medical supplies to Haiti. Four of the planes had Harry Potter names—Harry, Ron, Hermione, and Dumbledore—while the fifth was named DFTBA (Don't Forget to Be Awesome) in honor of Nerdfighters, a group that joined with the HPA on the campaign.

4. Education

The Harry Potter series largely takes place at Hogwarts, the school of witchcraft and wizardry. In the books, education plays a central role and the lead heroine is Hermione Granger, a young witch who demonstrates the role of books and education in fighting injustice and empowering people.

The Alliance has donated more than 120,000 books to kids in Rwanda, the Mississippi Delta, and New York City through its "Accio Books" campaign. They also helped build libraries at the New Beginnings Charter School in Brooklyn and in community centers across the Mississippi Delta.

5. Modern-day slavery and child labor

Dobby the house elf, one of the series' most beloved characters, is a slave who has been passed down through generations in the Malfoy family. When Harry tricks Lucius Malfoy, the family patriarch, into freeing Dobby, Harry earns the elf's undying loyalty. Dobby, as a free elf, achieves self-realization.

And Harry Potter fans have made the connection between house elf slavery and modern-day slavery.

HPA is currently pressuring Warner Brothers, which sells Harry Potter chocolate frogs (a common sweet in the books), to prove there is no child slavery in their cocoa supply chain. The Alliance even sells their own version of chocolate frogs made from fair-trade chocolate.

6. Voter registration

The Harry Potter books demonstrate the importance of civic participation by highlighting the government's role and its potential to overreach. More often than not, Harry Potter and his friends are at odds with the Ministry of Magic.

The HPA has used this connection in their "Wizard Rock the Vote" campaign. At 70 Wizard Rock shows across the nation, HPA volunteers walked around with clipboards registering more than 1,100 Harry Potter fans to vote.

7. Immigration and marriage equality

In the Harry Potter series, many "people have to live in the closet for simply being who they are," explains Slack. "Lupin has to live in the closet for his identity as a werewolf, Hagrid has to live in the closet for his identity as a half-giant, and Harry Potter is forced to live in the closet for his identity as a wizard. We all live in closets for multiple reasons. No one should have to, including for their immigration status or for their sexual or gender orientation." That's why the HPA raised more than $94,800 for equality initiatives.

In the 2012 election, club members helped in phone banks to add 900 calls to the Maryland DREAM Act to grant an in-state tuition discount to undocumented college students and to add support of marriage equality in Maine. In 2011 they made 6,200 phone calls and processed 214 digital postcards in support of marriage equality in Massachusetts and Rhode Island. The HPA also currently has a "Superman Is an Immigrant" campaign to support immigrant rights.

8. Structural poverty

The HPA is branching out into other books too. The "Hunger is Not a Game" campaign joined with Oxfam and the Hunger Games fandom to help end hunger. Their newest campaign is "The Odds Are In Our Favor" to raise awareness about inequality.