It's reporter Glenn Greenwald's perspective on the Edward Snowden story. As such, it's pretty scary. Most reporters don't know how to communicate using encryption. Thus, if you're a whistleblower handing over information to reporters, you're also handing that information over to whoever is monitoring those reporters' communications. The start of this story is about a security-minded hacker not handing over some information to Greenwald, who can't be bothered to set up all of this security stuff. (As it turns out, Snowden first passed the NSA documents over to Laura Poitras, who was able to use these things.)
The NSA's lies were scary, too, but you probably got those from the news instead of from this book; probably more current news, too.