Nina Fiore, executive secretary in the San Francisco medical examiner's office, confirmed to yesterday that Zhitomirskiy died in San Francisco. She would not say how or when he died.
Diaspora, an alternative to Facebook, was founded by four New York University students in 2010.
The site lets users keep control over their photos, videos and status updates while sharing them with friends.
Zhitomirskiy co-founded the website with Raphael Sofaer, Dan Grippi, and Max Salzber. The group raised more than USD 2,00,000 for the project by collecting contributions through the website Kickstarter.
According to Zhitomirskiy's profile on Diaspora, he's "super passionate about building a world of hacker spaces, maker culture, sharing, cycling, and life satisfaction."
In a September 2010 interview with New York Magazine, Zhitomirskiy said he wanted social network users to migrate towebsites that were more transparent about privacy policies.
Zhitomirskiy said he and his co-founders didn't set out to make money when they created Diaspora but to instead provide an "open platform" for users.
"There's something deeper than making money off stuff," Zhitomirskiy said. "Being a part of creating stuff for the universe is awesome."