If you create a book compilation of "Wikipedia's greatest hits", then you're stuck releasing the book as ShareAlike or negotiating with the copyright holder(s).
If you write a book about a particular topic and you use excerpts, quotes, or ideas from Wikipedia (and properly cite them), that's fair use. I'm sure there's some sort of ceiling on that (IANAL) which prevents you from copy+paste-ing broad swaths of text into your work and "citing" it.
The key is the citation, which is where the author screwed up. If you're using text/ideas from a particular source and not citing that source, then you're not covered under fair use and are obliged to follow whatever licensing system the original author wishes.
I'm surprised (and confused) -- can you really include a great number of large, verbatim or nearly verbatim blocks of text from Wikipedia, cite them, and not be called out for plagiarism?
What's to stop any author from saving themselves hours/weeks/years of effort by simply by copying text and sticking a citation at the end of the paragraph, as it appears was done in this case?
Reuse can never be 'plagiarism' if you cite your source and present it as a quote. Plagiarism is only presenting someone else's work as if it were your own.
Now, if the book is 99% other people's work, but all copying is cited, you might still run afoul of copyright laws for copying without permission. But it won't be plagiarism. Whether 'fair use' applies depends on a test where many factors are weighed. See:
Very roughly, the idea is: does your use add value for society without damaging the value of the original work? Using less is better than using more. Using for educational/nonprofit uses is better than trying to make a quick buck. Trying to make a buck in a new transformative way is better than trying to make a buck at the expense of (by replacing) the original work in the marketplace. Using just enough to have a conversation about the work, adding your commentary, is better than just reusing the juicy parts to save yourself effort. Etc.
If you create a book compilation of "Wikipedia's greatest hits", then you're stuck releasing the book as ShareAlike or negotiating with the copyright holder(s).
If you write a book about a particular topic and you use excerpts, quotes, or ideas from Wikipedia (and properly cite them), that's fair use. I'm sure there's some sort of ceiling on that (IANAL) which prevents you from copy+paste-ing broad swaths of text into your work and "citing" it.
The key is the citation, which is where the author screwed up. If you're using text/ideas from a particular source and not citing that source, then you're not covered under fair use and are obliged to follow whatever licensing system the original author wishes.