I can't find the reference, but isn't Spotify the service which stole the lyrics from another site? And then the other site added morse code on some of them to catch them red handed?
IIRC correctly, Genius added white space to some of their lyrics so that when Google scraped them, they could prove they got it from their site since the scraped content also had the random white space.
How did Genius become certain of that discovery? By hiding a Morse code message within some of the lyrics on its own site, the code being a series of curly and straight apostrophes which, when assembled, correspond to the Morse code for the word “REDHANDED” (as in, Google has been caught red-handed). Sure enough, those apostrophes showed up in Google results. But here’s the thing, though. After confronting Google with that evidence as described in a lawsuit Genius filed today against the search giant (with Genius describing that evidence as Watermark #1), Genius then decided to hide a second secret code (Watermark #2) inside its lyrics to further prove the lyrics are being copied.
They used it to spell out "REDHANDED" in morse code using apostrophes too..