Zuckerbergs second "most generous" in 2012

According to a new list, The Chronicle of Philanthropy names Mark Zuckerberg and his new wife Priscilla Chan as the second “most generous” donors of 2012.
First place as the biggest American philanthropist in 2012, goes to American business magnate Warren Buffett.
Zuckerberg and Chan who have a net worth of $9.6 billion donated $498.8 million to a non-profit organization, the Silicon Valley Community Foundation, through the donation of 18 million shares of Facebook stock.
The donation was announced on Facebook in December.
This is the second of two significant donations made by Zuckerberg in recent times. In 2010, the Facebook founder pledged $100 million toward Startup: Education.
Google co-founder Sergey Brin and his wife Anne Wojcicki came in fifth place on the list, after donating $222.9 million.