Jason Russell, whose 30-minute video sensation shone a spotlight on Joseph Kony's use of child soldiers in Uganda, was taken by police to a hospital in California last week after suffering what doctors described as a brief psychotic breakdown.

Videos posted online showed him pacing back and forth on the sidewalk, naked, in broad daylight, in an incident certain to raise questions over the viability of Russell's Invisible Children group.

"You always hear people say, 'I'm so stressed out, I'm about to go crazy,'" said Robert Thompson, director of the Bleier Center for Television and Popular Culture at Syracuse University. "Still, the story of all this happening and then he literally is wigging out is very odd."

He said the episode could serve to divert attention from the warlord to Russell. "Now whenever you see a Kony story, it's about the guy, not Kony."

Kony, accused of terrorizing northern Uganda for two decades, is wanted by the International Criminal Court for war crimes. He is accused of abducting children to use as fighters and sex slaves and is said to like hacking off limbs.

Russell's wife, Danica, has said her husband would remain under hospital care for a number of weeks, and might not be able to return fully to his work at Invisible Children for months.

In downtown San Diego, Invisible Children's office has been locked up.

Russell's Invisible Children co-founders, Laren Poole and Bobby Bailey, declined through a spokeswoman to be interviewed, as did the organization's CEO, Ben Keesey.

Keesey has attributed Russell's breakdown to the severe emotional toll of the previous two weeks in which the Kony video went viral. Even as the video drew attention to the warlord, it sparked criticism over what some called its misleading portrayal of current events in Uganda.

A spokeswoman would not say how or if Invisible Children planned to proceed with a planned April 20 day of action, in which viewers of the video were asked to paper their homes, lawns and cities with Kony posters to turn him into a household name.

RENEWED EFFORTS TO HUNT KONY

Analysts said the fate of the group may be largely irrelevant because it had already served the purpose of persuading millions to care, and policy decisions were taking shape.

"It's rare that we have literally millions of Americans calling for more engagement in Africa," Senator Chris Coons, chair of the Senate Foreign Relations subcommittee on African Affairs, told Reuters in an interview, noting his subcommittee normally received far less attention than it had since the "Kony 2012" video was released.

"I was both amused, pleased and proud that all three of my kids asked me what I was doing to stop Joseph Kony," Coons said.

Attempts by regional forces and foreign troops to corner the fugitive warlord have so far failed. But on Friday, the African Union said it would launch a 5,000-strong force in South Sudan to hunt him.

The African Union move is in addition to 100 U.S. military advisers President Barack Obama sent to the region last year to help Ugandan forces track Kony down.

Kony's Lord's Resistance Army is a shadow of its former self, numbering about 250 members, according to a December 2011 report published by the Social Science Research Council.

Some 200 of them are with Kony in the Central African Republic, and 50 others are in the Democratic Republic of Congo, the report said.

The video Russell directed, interspersing shots of his own young son with those of suffering Ugandan children, depicts children walking into the city center of the Uganda city of Gulu at night to avoid capture.

But active violence like that has not been seen in northern Uganda in seven or eight years, according to Laura Seay, a professor at Morehouse College, who studies conflict and community in central Africa.

"LRA victims are depicted as absolutely helpless," Seay said, characterizing the portrayal as neo-colonial and saying the film may have mischaracterized the nature of Gulu, where the number of children taking nightly refuge dwindled after a truce between government forces and the LRA in 2006.

"You have coffee shops and pizza places in Gulu. It's absolutely peaceful," she said.

Seay suggested that those whose interest in the region were piqued by the Invisible Children campaign turn their attention next to more active warlords in the region such as Bosco Ntaganda, nicknamed "The Terminator," and also wanted by the ICC for war crimes.

Ntaganda, a Rwandan operating in the Democratic Republic of Congo, is accused of conscripting child soldiers under age 15 to carry arms and fight in open conflict.

"He walks freely," Seay said. "I know where he eats dinner every night."

(Additional reporting by Marty Graham in San Diego; Editing by Cynthia Johnston and Peter Cooney)

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