This book was recommended to me by a co-worker who teaches technology. I had heard of the basic concept or premise of the book and knew there was a TEDTalk by Eli Pariser about it, but hadn't watched it yet. The basic idea is that Google, Facebook, news media, and other online sites are personalizing search results. This can be bad for a variety of reasons.
The simplest and least concerning is the ease of communication. It is more difficult to suggest to someone that they do a Google search and then recommend the xth result down, because their results will be different. More concerning is that your views are not going to be challenged, so when Facebook detects that you read more posts and linked articles posted by your Republican friends your Democratic friends posts show up less often in your news feed. Or personalized ads that prey on your weaknesses, like you are more likely to spend money on particular items when you stay up late the day after payday, or right after a bad day at work. To the really concerning, data collected about your browsing history and shopping history may be used to deny you credit or a job. There are a lot of scenarios that are worked through in the book, which probably brings me to my on disappointment with the book, it is hard to discern what is already happening and what could happen with internet personalization. Will things actually get as bad as he claims and will it matter if we do everything to keep ourselves safe? After all, Google's personalized search results take into account where you are searching from, what type of computer you are using, and what browser you are using. So then, even if I keep all of my personal information private, will it matter if I'm still getting individualized search results for other reasons.
Admittedly, I'm not as careful on the internet as I used to be. I've handed much of my life over to Google and their products. I used to never have a password stored on my computer or in my browser, but most of them are now. I resisted cloud storage for a long time because I liked to have personal control over my files, and I do still have backups, but the cloud offers a lot of convenience. I'm not one to believe that we must give up personal freedoms for internet security, just like I disagreed with giving up those freedoms for national security in the name of fighting terrorism. But something does need to be done. Europe has already forced webpages to simply put up notice that they use tracking cookies and have, or are working on, making it a requirement that data collected about you be available to and contestable by you. Probably the greatest part of the book, was the last fifth to even quarter where he recommended what could be done at all levels- from the individual to the society to the companies that provide services, to governments.
I can't say that I've changed a lot of my online behavior since reading the book, except now I check Facebook probably monthly instead of weekly, although I'm not sure that can be blamed on the book, but I am more aware of the issues that can arise and certainly am keeping an ear towards company and government policies on the Internet and technology.
PS- a tool I recommend that is related to internet security and tracking that I picked up from another TEDTalk is Collusion.