Jason Russell THE NAKED MELTDOWN Caught on Tape

3/17/2012 10:05 AM PDT



TMZ has footage of "Kony 2012" honcho Jason Russell in the midst of his naked meltdown in San Diego ... pounding his fists in anger and screaming maniacally. [UPDATE: TMZ has obtained a close-up video from Russell's meltdown. CLICK HERE to see.]

As we previously reported, Russell was detained by police yesterday ... after witnesses say he was running around naked and making sexual gestures.

Russell was held on a 5150 psychiatric hold ... so authorities can decide if he poses a danger to himself or others.

A rep for Invisible Children says Russell was suffering from exhaustion, dehydration, and malnutrition as a result of a strenuous PR campaign.