Facebook admins routinely delete comments on their page, if they don't meet their standards. Or to silence critical voices.
Usecase: You want to investigate, which comments on a specific Facebook page are deleted.
Goal: Find patterns, which suggest that criticism is censored by admins.
What you will need in advance
You will need an App ID from Facebook. myAppID = app ID from app you created at developer.facebook.com myAppSecret = app secret (see above)
Setup instructions are here: http://thinktostart.com/analyzing-facebook-with-r/
Facebook restricts requests to a maximum of 500 replies (likes, comments). rfacebook does support paging through all content, but it seems like this is buggy.
This means: a comment might be registered as deleted while actually being online.
You can ping the comment's ID to verify it being offline. Ascript will be added shortly to help with this.