“Pure scrambling fonts already existed…We wanted a mechanism with actual consequences: scrape without asking, and you can’t tell if what you took was real.”
ShieldFont swaps roughly 25 percent of words in the HTML and uses OpenType substitution to render the originals back for human eyes. The scrambled text is what sits in the markup, so screen readers, copy-paste and site search get the poisoned copy too. It costs an 800 KB font download per visitor. The authors say outright it stops nobody determined, which leaves publishers breaking their own pages because no court or legislature gave them anything better.