"Digital whistleblower and Wikileaks founder Julian Assange was Time’s readers’ choice to be the magazine’s 2010 Person of the Year with 382,206 votes, but [Time's Managing Editor, Rick] Stengel said he considered the long-term impact of the Harvard-dropout-turned-social-network-mogul [Mark Zuckerberg]—not just the past year’s," Mediaweek reports.
Thus Zuckerberg was named Time’s Person of the Year and not Assange.
According to the article, Stengel added, "When I make the choice, I think of [what] has actually affected people’s lives the most [in] the past year. Five years from now, who’s going to look smart? Julian Assange has been in the news a lot lately. I think five years from now, he’ll been an asterisk. If you really wanted to, [you would] make [leaker] Bradley Manning. Julian Assange was the wine bottle, and Bradley Manning supplied the wine. In the grand scheme of things, it will be a footnote to history.”
Stengel continued, the article said, that "Zuckerberg, meanwhile, created a new system of connecting people that ‘is the connective tissue for nearly a tenth of the planet. Facebook is now the third-largest country on Earth and surely has more information about its citizens than any government does.’ "
One misconception some members of the public have is that Time’s Person of the Year is a designation honoring someone for a positive contribution to society. In fact, it is the person who has had the most significant impact. Thus Hitler was a Time Person of the Year–then called Man of the Year–for 1938.