There is now the possibility to annotate the online version of the textbook using hypothesis, a social annotation platform. You'll need to create a (free) account on web.hypothes.is to add your own annotations and reply to other people's annotations. You can post your annotations publicly for all to see (like this post) or privately, if you are just taking notes for yourself. Participants in my classes are encouraged to post their annotations and replies in the class' private group. Ask me for the link, if you didn't receive it.

If you don't want to see what other readers have highlighted and annotated, click on the "eye" button in the top-right corner of your browser to hide all annotations.