How do I turn off the preview of Facebook notifications on iPhone?

So, on iOS 5 it is possible to turn off the preview text messages so that the alert on the Lock Screen just says “New Text Message” under the sender’s name.

I was wondering if it’s possible to do the same for the Facebook app?
Ideally just saying something like “Facebook: New Message from X”, or “New Wall Post”, or even just “New Notification” so that you have to go to the app to see what it is?

Basically I want to know when I have something on Facebook (be it a notification or message), but don’t want anyone else to be able to see it..

Thank you