Bothers me, too, Allitrya. I've recently made up a bunch of stitch markers, and intend to open an Etsy store, perhaps next month. And of course some of the markers are in colors which correspond to the House colors. I had intended to use Harry Potter to tag those markers ... now I suppose I'd better not. But in that case, how can I tag them so they'll come up on a search without putting myself into an untenable legal position?
This may not (please note I said 'may not') be all JKR, either. I know nothing, really, about publishing, but I do know a little bit about other businesses and her publisher and/or lawyers may also be behind this. I don't know how much personal choice she may/may not have in such issues.
But it sure is discouraging. Will she/they be after things like sock patterns and knitters next?