Many people have the custom to recite the prayer "Ana B'choach" after the initial six chapters of Tehillim said in Kabbalas Shabbos and before "Lecha Dodi". Based on the fact that it references certain uncommon names of God and that the custom's origin seems to be the Sh'la, I would identify this prayer as being of a kabbalistic nature.
Now, I don't know if this has basis, but I've always felt that kabbalistic practices should be kept to one's self as private practices. This is why, although I personally do not recite the prayer, I think it is proper that it is not customarily recited out loud, but rather quietly in an undertone.
However, this past week, the chazzan of the minyan I was praying with decided to have everyone sing it out loud in unison to a popular tune. This made me extremely uneasy.
So I ask: Is there anything really wrong with what this chazzan did? Is there a reason why the prevalent custom is to recite it quietly and individually?