I had never heard of Rap Genius before this Heroku thing and their app is aimed at dissecting the types of textual messages that are being exchanged back and forth here. Seems like they decided to take the "pick a fight" approach to publicity quite literally...
Although I'm getting bored of this little scuffle, I am glad that they made some noise initially because it let me know that I wasn't crazy. I was trying to profile, understand, and optimize a Heroku app and ultimately gave up because it was relatively easy to migrate.