Jason Russell
Brendan McDermid/Reuters/Landov
Russell, 33, was found wearing only his underwear and was masturbating and vandalizing cars Thursday morning, police Lt. Andra Brown tells NBC7 in San Diego.
Russell's video, which has been embraced by a number of celebrities, targets Joseph Kony, the leader of a Ugandan rebel army accused of abducting more than 30,000 children over the past 26 years and forcing them into slavery or sex.
Ben Keesey, CEO of Invisible Children, says in a statement that Russell was "unfortunately hospitalized yesterday suffering from exhaustion, dehydration, and malnutrition."
"He is now receiving medical care and is focused on getting better," says Keesey. "The past two weeks have taken a severe emotional toll on all of us, Jason especially, and that toll manifested itself in an unfortunate incident yesterday.
"Jason's passion and his work have done so much to help so many," the statement continues, "and we are devastated to see him dealing with this personal health issue. We will always love and support Jason, and we ask that you give his entire family privacy during this difficult time."
• Reporting by JOHNNY DODD