Here's the thing, though. They stole the joke from Tom Ammiano. Who, actually, was serious about it. See, Tom's idea is that the city's WiFi plan should involve setting up broadband through the sewer system when the city gets around to fixing the sewers.
So, to make a long story short, or a short story short in this case, Google's big LOL joke was in actuality, a dig at Ammiano and his plans. Because, of course, Google and Earthlink are all set to give the city free WiFi but is primarily opposed by the Board of Supervisors with Ammiano being one of the critics of the deal.
Sergey & Larry are such kidders, aren't they?