AP Photo

Last October, while hundreds of protesters were encamped in Zuccotti Park, a handful of people occupied a glass building in downtown Washington, D.C. Wearing sheepish grins and business-casual attire, the 99% they were not; one demonstrator said he worked for Grover Norquist. “GOOGLE: DON’T MARK ALL AS READ,” pled a poster outside the Internet company’s D.C. headquarters, where the aggrieved customers had assembled.

That week, on the heels of launching its long-awaited social network, Google was to make significant — and feature-breaking —...