We have a wildcard CNAME pointed to our GitHub Pages, e.g. *.example.com points to example.github.io.
When navigation to a certain subdomains, e.g. ftp and email, for which there are no pages, instead of the expected 404, we see content from “PDF Books Catalog”.
Searching Google, this is apparently not isolated to just us: http://lmgtfy.com/?q=PDF+Books+Catalog
Today we received a DMCA take down notice for this.
Is anyone else actively experiencing this?