Health issues?
You have at least half a dozen active WiFi access points active nearly everywhere in San Francisco. One additional network is not going to add more.
This is more a sign of how disconnected loony-left supervisors in San Francisco are from reality. People like Chris Daly are vociferating about the sweet deal Google is getting from "selling" free service, and is demanding they give free PCs to various pet projects to atone for this.
Given that San Francisco's budget is greater than the entire GNP of Mongolia, is close to that of Chicago or Paris, both significantly larger cities, and that we get precious little value for our money, it's probably a good idea not to turn the network into yet another boondogle for incompetent politicians to mismanage at the taxpayer's expense, but I wish they would stop looking at a gift horse in the mouth and stop obstructing the project already. San Francisco was supposed to be the first Wi-Fi city, but has already been overtaken by Philadelphia, London, Paris and many others.