There's a lot of this book that's not really about 4chan or Anonymous, but about the development of unmoderated or awfulness-seeking sites on the web. The book makes for a primary document in its own right, insofar as it shows how someone can recognize how hostile certain spaces are to women and still not connect that with his own judgments about those spaces' "importance." Stryker contends that 4Chan is the source of most web memes and therefore the most fascinating place on the web. Maybe a biographer often buys into a subject's own narrative.
I'm more interested in the gender stuff: Stryker reports that there aren't many women on 4chan (how we know this is unclear, but I'm not arguing) and that it's pretty hostile to women, except for female cosplayers and for visitors to /cm (Cute/Male anime, separate from the main Cute anime board--which does clearly reflect the marked status of women). So "[t]he 4chan adage `There are no girls on the Internet' suggests that anyone claiming to be a woman is actually a man either trolling or getting a sexual thrill out of posting as a woman," and women who post pictures of themselves get encouraged to strip, so that "4chan's relationship with women is weird and sad." But not 4chan's users? Or only when they're on 4chan? He also says that yaoi is naked male anime but yuri is femslash; this may be true of how 4chan boards define the terms, but somebody is a little nervous about anime guys having sex with other guys. 4chan also revels in the use of offensive terms, and Stryker has a good conversation with Lisa Nakamura about the thrill of shock value and the desire not to be held responsible for consequences of racist and sexist abuse. She says, "A lot of disenfranchised, disaffected white people feel like they're also fighting the man, they're also on the edges, but in some really important way they are not." He says, in response, that homosexuality is much more accepted on 4chan than non-whiteness, while by contrast the US in general has "gotten over its fear of racial minorities to a much larger degree than its fear of gays"; I wonder how he knows this.
Getting back to the most interesting place on the web: Stryker is surprised to find out that the founder of Encyclopedia Dramatica, which cataloged some of 4chan's greatest hits, has zero interest in 4chan. She founded it to document Livejournal drama, which he then discusses for a couple of pages and then leaves behind. This underscores just how much this is a book about what (some) men find interesting and important; Stryker doesn't seem to get that some people's narratives start and end in different places, and seems bemused by the ED founder's claim that she really only cared about LJ.
The book ends with broader discussion about anonymity versus identifiability on the web, and as usual there's short shrift given to persistent pseudonyms/autonyms that aren't connected with government ID. Stryker is supportive of anonymity; as 4chan's founder says, it's a way to fail and not be stuck with the consequences of that failure forever, something that people a generation ago were able to take for granted. One can resist identificatory practices on the internet or one can negotiate with them; anonymous stands for resistance, though not always successfully. (I would love to read a book about how privacy/reputation worked before the industrial age, how that changed as Westerners started moving away from their birth locations more, and what we can learn from past experiences.)