Actually, they were mostly just very hostile and unpleasant. This is among the many reasons why we're probably staying independent and printing the book ourselves - so that the digital version stays unencumbered among other things.
pdftk $(ls -tr *.pdf) cat output DeepLearningBook.pdf
Out of respect for the authors' contract, I won't post the resulting file here, but anyone can reproduce it with about 5 minutes of work.Preview: http://i.imgur.com/5OXv28R.png
Call me evil but I did it:p