They may not have magic, but they're sure doing wonders.
One group of Harry Potter fans has set out to harness the energy of the franchise's massive fan base for charitable and political causes.
"These books carry great power in them," said Andrew Slack, executive director and co-founder of the Alliance. "There are all these parallels to our world."
If Hermione Granger, a central character in the Harry Potter series, knew the conditions of farmers in third world countries, she would be active for fair trade, too, Slack said. After all, Hermione started an organization in the fourth book to gain basic rights for house-elves.
The Alliance hosted "Lumos" parties around the world for the film's release. Lumos is the spell Harry and the other wizards use to create a light at the end of their wands -- just as the Alliance hopes to bring light to its causes.
Slack spoke at a movie theater in New York City, where the group was collecting petitions in the name of fair trade.
Members of the Alliance call themselves a Dumbledore's Army for the real world. Dumbledore's Army is the group Harry started to train his fellow students to defend themselves against dark magic.
"The Harry Potter Alliance is sort of bringing a new kind of activism into the world," said Paul DeGeorge, a co-founder of the group and one half of the punk rock band, Harry & the Potters.
He said that fans now are doing exactly what Harry and his friends do in the books, fight for what's right.
"We're involving more people who wouldn't normally have an avenue for social justice issues in engagement," said Jennifer Dorsey, communications director for the group.
Dorsey said the parallels to the novels continue. A number of characters in the series fight discrimination, so the Alliance has taken up marriage equality. Since the group started in 2005, the alliance has worked on stopping genocide and increasing literacy, as well.
After the earthquake in Haiti, the Alliance led a fundraising effort that donated enough money to send five cargo planes of lifesaving supplies there.
J.K. Rowling, the author of the Harry Potter books, posted on her website that the Alliance "really does exemplify the values for which Dumbledore's Army fought in the books."
The power of fantasy and myth drives people to groups like the Alliance, said Sangita Shresthova, research director for the Media, Activism, Participatory Politics (MAPP) project at the University of Southern California. The group is studying the why socially engaged fan groups like the Alliance are growing.
"It bridges being a fan of the stories and wanting to do something and to feel like you're making a meaningful contribution to the world," said Shresthova.
She added it is important because young people are engaging with a mission rather than a single issue.
Slack sees such activism as the future.
"Imagine if we can get a fraction of the people who saw 'Avatar,'" Slack said, "to walk out of there and say, 'If we want to protect the Pandora of the real world, we have to fight the sky people and the coal industry.'"