I thought I had read that DAT (digital audio tape) detected altered notes/frequencies to avoid copying, but it appears to only have been a proposed idea. http:

I thought I had read that DAT (digital audio tape) detected altered notes/frequencies to avoid copying, but it appears to only have been a proposed idea. http://en.wikipedia.org/wiki/Serial_Copy_Management_System#History http://en.wikipedia.org/wiki/Serial_Copy_Management_System#H... People have done pitch-shifting and other tricks to get around YouTube's Content ID in the past. And the fictional word "esquivalience" was added to the New Oxford American Dictionary to detect copies. http://en.wikipedia.org/wiki/New_Oxford_American_Dictionary#Fictitious_entry http://en.wikipedia.org/wiki/New_Oxford_American_Dictionary#...