👀
RT @json_dirs@twitter.com
More fun publisher surveillance:
Elsevier embeds a hash in the PDF metadata that is *unique for each time a PDF is downloaded*, this is a diff between metadata from two of the same paper. Combined with access timestamps, they can uniquely identify the source of any shared PDFs.
🐦🔗: https://twitter.com/json_dirs/status/1486120144141123584