The Chronicle's top 50 list has critics delving deeper, looking at "relative generosity" and wondering if some of the richest are giving enough.
"We often write about the generosity of philanthropists. But what about rich folks who are giving — but not really pulling their weight? Inside Philanthropy’s calls out some billionaires not because they’re not giving, but because they’re not giving ENOUGH based on how much cash they’ve got stuffed in the mattress." -- Joe Garofoli, SF Gate