Three stars for plot and characters, four stars for interesting ideas, would give this 3.5 stars if I could. Doctorow is a futurist; a tech fan; a forward thinker. His novels tend to explore slightly futuristic dystopias, extrapolating elements of the current direction of technology into a future extreme, and this does the same. It's structured as a novel but I think it's as much an exploration of "what if" that he's working out as he's writing. What if in the future we reach a post-scarcity world where technology (3d printers and such) can provide enough for ALL humans to live in comfort? But of course, those at the top, the "zottarich" (zotta being a bigger number than mega) feel entitled to their far bigger share of the wealth than those beneath them, so the usual problems of homelessness and starvation continue to exist. The gap between the haves and have-nots gets wider, the working class gets poorer and more hopeless, and employment becomes scarcer.

In the midst of this, a movement arises out of the 'maker' culture calling themselves 'walkaways'. The current model of society as enforced by the zottas is clearly not working; so they simply walk away. Walk out into the wilderness, or into unwanted land or even uninhabitable areas, taking nothing but the clothes on their back and portable fabbers (fabricators, the descendents of 3D printers) and sometimes not even the first. And they construct smart encampments based on open-source blueprints and basically live in a socialist commune environment where all work is shared, and the smart buildings automatically highlight areas where someone needs to do something (like fix something, or put away dishes) and (in communities that want to) keeps leaderboards of everyone's contribution ratings.

The story mostly follows super-rich-girl Natalie, disillusioned with her zotta father's selfishness, and a couple of her friends, who decide to turn walkaway and join a nearby community. Over a span of several decades her father tries to get her back through various means up to and including kidnapping; the "default" society they left behind tries to eliminate the walkaways, seeing them as a threat to "normal" existence; and the walkaways themselves become a highly tech-savvy almost guerrilla-type organization creating distributed networks, redundant information-sharing methods, and extremely sophisticated methods of anticipating, escaping, or undermining attacks from 'default' over the years and across the world. Along the way they also discover how to upload human consciousness into computers, a fact which seems as if it should and could have been a bigger plot point in several ways than it actually turned out to be.

The book is used as a vehicle to examine and discuss a lot of interesting theories and ideas, especially the artificial and unstable nature of the zottarich, the potential of fabricators to create a world of plenty, and the idea of communal work-sharing settlements. You may or may not agree with all Doctorow's conclusions, but they're interested to read either way. As a novel however I didn't feel it was quite as successful; it felt a bit disjointed, many of the characters were not particularly likeable, and the plot seemed to come second to the exploration of the theories above. Also lots of random sex thrown in, which you may or may not enjoy but didn't seem particularly relevant.