a reverse captcha, blacklisting residential ips and forcing anyone suspected of being human to solve a captcha only readable by robotic eyes, only understandable by odd OCR subterfuge (to all others, they appear as messes of lines, random dots)
@Pummelator every now and then there's a leak of what the interface looks like and it's always hard to decipher the source code, however, is praised as being beautiful, elegant, despite nobody being able to show it