Hi Folks! In this post I will show you how to implement a controller method that is supposed to delete Facebook data from your website, a.k.a. Data Deletion Callback URL. First, clone the repository from GitHub.
Clone the repository here.

Open the DataDeletionCallbackURL solution and head for a controller called SocialNetwork. There will be a method called FacebookDelete. The only important detail I should mention is that the hash is generated using the raw data (Request.Form["signed_request"]), not the one from the split variable, because the extra characters and the replaced characters result in a different hash (and the signature validation fails).
In the method, the only thing you will need to do is replace "Put your APP Secret here" in line 43 with your own app secret. Now, you will have to implement the FacebookInfo method and inform the user that the data was successfully deleted from your website. And that's it!
Don't forget to update the User Data Deletion field in your app settings.

Enjoy!