By Erica Orden and Nicholas Bariyo

A video campaign about a fugitive rebel leader in Africa has exploded into a viral online phenomenon, igniting debate about the group behind it and the threat posed by the rebel himself.

The 30-minute video, “Kony 2012,” focuses on Lord’s Resistance Army head Joseph Kony, who is wanted by the International Criminal Court for crimes against humanity and war crimes including murder, sexual slavery and using children as combatants—sometimes forcing them to kill their own parents—in Uganda and its environs for more than 20 years.

The video features interviews with children in Uganda who say they are fearful of being captured and killed by the rebels.

By Thursday afternoon it had generated more than 44.7 million views and over 170 related video clips from the time it was uploaded to YouTube on Monday by Invisible Children Inc., a San Diego-based nonprofit, according to online measurement firm Visible Measures Corp.

Twitter users mentioned Kony more than 950,000 times on Thursday, according to social- media analytics firm PeopleBrowsr, with tweets by public figures including Rihanna, Alec Baldwin, Sean Combs, Ryan Seacrest, Bill Gates and Sen. Patrick Leahy (D., Vt.).

Invisible Children, founded by three filmmakers, turned to Twitter and Facebook to encourage its followers to share the short film, donate to its campaign to raise awareness about Mr. Kony and sign a pledge “to help bring Kony to justice in 2012.”

The nonprofit’s Invisible Children Protection Plan, according to financial statements, is a five-step strategy that includes building an early-warning radio network “to facilitate twice daily security broadcast and early-warning communications,” and deploying search-and-rescue teams.

Ugandan officials, nongovernmental organizations and others have questioned the group’s capacity to enact change on the ground, such as enabling family reunifications, as well as the utility of its focus on Mr. Kony.

A spokesman for Uganda’s defense and army, Felix Kulayigye, said Mr. Kony is already a spent force. “The world is just realizing the evil in this man, but these are the things we have pointed out countless times in the past,” Mr. Kulayigye said. “Good enough, we have decimated his capabilities now.”

The United Nations said in a November report that fewer than 500 combatants operated under Mr. Kony’s command, but said concern remained about the LRA’s ongoing attacks on civilians, “which have resulted in deaths, abductions, looting and the displacement of some 440,000 people.”

In October, the White House authorized up to 100 U.S. special-operations trainers and military advisers to assist African forces searching for Mr. Kony and other leaders of the LRA.

Radhika Coomaraswamy, the special representative of the U.N. secretary-general for children and armed conflict, said attention generated by Invisible Children is useful and welcome if the group’s work is performed in cooperation with U.N. programs.

Others have questioned whether the group’s capabilities extend beyond its skill in attracting attention. “While this is a very impressive example of viral marketing, it’s raising awareness for a cause that doesn’t need awareness,” said Scott Gilmore, chief executive of Peace Dividend Trust, a nonprofit that focuses on streamlining inefficiencies in humanitarian operations. “Those 30,000 kids who were kidnapped, this isn’t going to un-kidnap them.”

“That’s a naive and sad world view,” said Jesse Derris, a spokesman for Invisible Children. “The idea that you should do nothing unless you can do everything is exactly what we’re trying to avoid.” Mr. Derris declined to comment further on the group’s efforts.

The film features Invisible Children co-founder Jason Russell, who in one scene shows his son, a toddler named Gavin, a photo of Mr. Kony, to whom he refers as “the bad guy.”

“Joseph Kony, he has an army, OK?” Mr. Russell tells Gavin. “And what he does is he takes children from their parents, and he gives them a gun to shoot and he makes them shoot and kill other people.”

“I couldn’t explain to Gavin the details of what Joseph Kony really does, because the truth is, Kony abducts kids just like Gavin,” Mr. Russell says in a voice-over.

Angelo Izama, a Ugandan analyst with local research group, Fanaka Kwa Wote, said the campaign is misleading since Mr. Kony’s crimes in Uganda are from a bygone era. “What does it profit to market the infamy of a man already famous for his crimes and whose capture is already on the agenda?” Mr. Izama said.