Silicon Valley has some of the country's more dizzying gaps in income inequality. Wealthy enclaves are built besides some of the Valley's poorest neighborhoods, leaving family services underfunded and municipalities writing laws that punish the poor. Now their own congresswoman is calling out tech CEOs for not doing enough to help:

The Bay Area, ground zero for apps that will change the world and the investors who finance them, is one of the least charitable places in America. The Chronicle of Philanthropy ranked the 50 largest metropolitan areas. San Francisco was no. 45 on the list.

A new viral sensation is sweeping our nation's billionaire technologists: Daring their rich friends to either donate $100 to ALS research, or dump a bucketful of ice water over their heads. The latest mogul to save a hundred bucks is none other than our frugal friend Mark.

"Run for the hills. Leave now. You have to find shelter. They have a cheese sommelier."

In case you missed the all the glowing profiles of Salesforce CEO Marc Benioff this week, the billionaire's philanthropic efforts have crowned him "the most influential man in San Francisco." And he's wielding that influence to "shame" his rich friends into giving back.

Philanthropy today: Larry Page, the Google co-founder with $32 billion and little record of altruism, says he'd prefer another tech billionaire inherit his estate instead of leaving it to charity.

Every year, the Chronicle of Philanthropy puts out a list of the largest donors. (Mark Zuckerberg came out on top in 2013.) But Inside Philanthropy calls that a vanity metric. Looking at the percentage of wealth an individual has given away, they argue, is the best measure of generosity.