I read both this version and the 3rd edition(had already read the 2nd by the time I found that the 3rd edition was required for my CS280 course, so figured what the hell, since they were different enough to warrant a second reading)
This book is not necessary for anyone who's been living on the internet since the late 90's. If you've been addicted to slashdot, reddit, and other tech-related social websites, it provides nothing but a tangible representation that certain things in the past did actually occur. Those certain things that you may remember well, if you're old enough, or if you've trawled archives of old tech radio shows, old zines, etc. It is a reference, a starting point.
Baase has clearly put a lot of effort into this book, especially the chapter on privacy(which her passion in this issue shows in the depth of discussion), but personally, I didn't really learn anything from it. The ethical issues I've seen before, the technology and specific events mentioned I've almost entirely encountered. It's a sign of the times, however -- 20 years ago books like this were needed to become ethically grounded in the field. Today, it's a footnote.
Save your money, and trawl[...] instead. Join your local 2600 and linux user group, and talk to people in your community. Find out what they are concerned of, aware of, in regards to computer technology, and research it. Because I guarantee the ethical choices that you'll make after interacting with real situations, with real people, and helping people with real problems, the ethical lessons that you will learn, will grossly trump anything this sterile, pinned-butterfly version could.
If you're a historian, this is probably not a bad buy.
I'm tempted to give it more stars for it's thoroughness, but it really wasn't a match for me, so I just can't.