Can't Find A Facebook Troll

I was talking to a friend about a thread I saw with a Facebook troll when someone wrote a nasty/unspeakable comment under something like "Jesus is my savior." Then once people would respond to the nasty/unspeakable comment, the troll would delete their comment and the people below look like they are responding to the original post.

Is there a name for this type of trolling? Does anyone have good examples?