An individual wage near $20 an hour, or about $41,600 per year, could be the basis of a sustainable working-class life in many cities and regions of the U.S.

But not so in Silicon Valley, where many (non-entry) jobs at established technology companies pay in the low six figures per year or more.

From San Francisco south to San Jose, anyone earning such an income would be hard-pressed to save enough for a down payment on a home or for a child's college education.

Faced with that daunting reality, 500 or so people who work at the cafeteria at Facebook's headquarters in the city of Menlo Park, California, this month voted to unionize.

Those who voted to join the union, Unite Here Local 19, in hopes of pushing up wages, included a couple named Nicole and Victor, who are living together with their three children in a garage not far from Facebook's campus, according to a report in the The Guardian.

Neither Facebook nor the food service contractor that runs the cafeteria, Flagship Facility Services, opposed the union drive, the report said.