If an author publishes work and I copy it for my own purpose, then I have stolen something from the author (and publisher, if the copyright is held by both). But if I quote something of the author’s for the purposes of discussion, then I have committed no theft, in pretty well every jurisdiction that is cosignatory to the Berne Convention on Copyright. It’s called “fair use“. In fact, the whole point of publishing is to have people discuss what you publish, right?
Not according to Lisa Richards of the Society of Chemical Industry, it isn’t. She sent a nasty letter threatening legal action (by the publisher’s lawyers!) if Shelley at Retrospectacle didn’t take down a part of a figure she copied from an article she was discussing. Follow the last link to see the details.
And complain wherever you can. This sort of attempt to bully people who discuss ideas is comtemptible.