I can't speak for the other three cities, but San Francisco has a number of problems that would make it difficult for a Google Fiber rollout.
First, AT&T is already in the process of rolling out fiber to the home, or in some cases, fiber to the node with last mile copper. They have faced nothing but problems trying to do this from people in the city: http://www.sfgate.com/bayarea/article/Groups-sue-S-F-trying-...
Density can be a nice benefit, but lack of space makes it hard to place the equipment necessary to serve fiber.
Second, a local provider Sonic.net is also rolling out fiber by taking the approach of starting in the closest thing San Francisco has to a less dense suburb (the Sunset). They've faced exactly the same issue (battles over placing Utility boxes).
First, AT&T is already in the process of rolling out fiber to the home, or in some cases, fiber to the node with last mile copper. They have faced nothing but problems trying to do this from people in the city: http://www.sfgate.com/bayarea/article/Groups-sue-S-F-trying-...
Density can be a nice benefit, but lack of space makes it hard to place the equipment necessary to serve fiber.
Second, a local provider Sonic.net is also rolling out fiber by taking the approach of starting in the closest thing San Francisco has to a less dense suburb (the Sunset). They've faced exactly the same issue (battles over placing Utility boxes).