We stumbled across this one in the CrackBerry forums earlier and couldn't help but pass it along.
As you may or may not know, BBM has an option to share what music you listen to in the media player as your status update. This feature is disabled by default but if you happened to toggle it on at some point, it can of course be disabled if you know where to look.
As it turns out it's a good idea to disable it if you plan to share anything other than what music you're listening to.
In BlackBerry 10, videos played in the browser invoke the media player when played, thus triggering as a "music" update.
So many videos that you play from within the browser will be shown as music status updates on BBM -- this goes for any videos that you may want to be kept private as well.
So before you go browsing around and watching videos you may want to keep to yourself, make sure you follow the steps below to disable showing your music updates in BBM.
In BBM swipe down from the top bezel then choose Settings
Toggle Show What I'm Listening To so it shows Off
Tap Back to save
Discuss more on this in the CrackBerry Forums