Susan Crawford, writing for Backchannel: Last week, San Francisco became the first major city in America to pledge to connect all of its homes and businesses to a fiber optic network. I urge you to read that sentence again. It's a ray of light. In an era of short-term, deeply partisan do-nothing-ism, the city's straightforward, deeply practical determination shines. Americans, it turns out, are capable of great things -- even if only at the city level these days. [...] San Francisco's dilemma is a compact form of the crisis in communications facing the rest of the country: Although fiber is the necessary infrastructure for every policy goal we have -- advanced healthcare, the emergence of new forms of industries, a chance for every child to get an education, managed use of energy, and on and on -- the private sector, left to its own devices, has no particular incentive to ensure a widespread upgrade to fiber optic connections. Comcast dominates access in the city, but has no plans to replace its cable lines -- great at downloads, not so great at uploads, no opportunity to scale to the capacity of fiber thanks to the laws of physics, and expensive to subscribe to -- with fiber. And its planned enhancements to its cable lines have, in other cities, resulted in a product costing $150 per month. AT&T will say it's upgrading to fiber in San Francisco, but so far its work in many other US cities has been incremental, confined to areas where it has existing business customers to serve or where it already has fiber in place. Other, smaller providers similarly have no plans to do a city-wide upgrade, leaving San Francisco with a deeply uneven patchwork of connectivity. Just as in the rest of the country, poorer and less-well-educated San Franciscans tend not to subscribe to a wire at home, but instead rely wholly on smartphone data plans -- no substitutes, given their expense and throttled capacity, for what's possible using a wired connection.