After iOS 5 update, where is Ping in the Music app?

Hi all. Before the iOS 5 update, when I was listening to a song with my Music app (previously called iPod), when I touched on the display to see the details of the song playing, there were 3 icons: Repeat, Ping and Random.

The Repeat and Random icons are still there after iOS 5 update, but where is the Ping icon? You know, the one with the "thumb-up" that, once you tapped on it, it turned on blue to say that you liked that song. That icon has disappeared.

Do you know where is it? Thank you very much. Bye!