Does any1 know what the hidden message in disturbia is?

I always used to really like the song 'Disturbia' by rhianna, but my friend told me that because she is now working with Jay-Z, if u listen to Disturbia backwards then it has a hidden message, and its really creepy? I know it sounds silly, but I fink if i listened to it then I've get really creeped as (as am scared easily) but if any1 else knows could they tell me, cos i wanna no what I have been listenin to all this time??