Genius used a similar technique to check whether Google was scraping their lyrics. Apostrophes in selected song lyrics spelled out "red-handed" in morse code.
> Google blames the issue on third-party licensing partners. "The lyrics displayed in information boxes on Google Search are licensed from a variety of sources and are not scraped from sites on the web," the company said in a statement.
https://www.pcmag.com/news/genius-we-caught-google-red-hande...