Lots of Facebook users are facing a general issue that anyone can comment on their public updates, including people who are not added to their friend's list. Well it's not that there is something wrong with Facebook, it's just a simple setting that most of the users are missing.
The thing you are missing here is the subscriber settings. Mostly people look for this option in Privacy Settings but it's actually hidden in your subscriber settings because Facebook is still continuing with its old habit of making things confusing for users. Now all you have to do is to go to your Account settings and then click subscriber settings tab. Alternative you can click the link below:
Now see settings for "Subscriber Comments" and select accordingly. Select Public (Including Subscribers) if you want anyone to comment or like your public stuff. This option is by default and this is the reason why anyone can comment on your Cover Pictures if your subscribers are enabled. You can disable public comments by select Friends from the same drop down list of "Subscriber Comments".
This is it; you don't have to click save or anything, settings will be saved automatically. Please drop a comment below for any doubts.
-- This Post How to control who can comment on your public updates is Published on Devils Workshop .