Andrea writes: I would like to do the opposite of your tip on how to unsubscribe from “likes” and “comments” from friends. Can I prevent my friends from seeing my likes and comments on posts I make to friend if they’re not linked with each other?

For example, Fred is not a friend of Bob’s, but I am friends with both. I don’t want Fred to see what I like or comment on Bob’s status. Make sense?

Hi Andrea! Great question, and yes—keeping your comment on Bob’s post private from Fred sounds perfectly simple.

Indeed, you may have seen a viral message that was making the rounds on Facebook a few months ago that seemed to address this very issue:

Please do me a favor: hover over my name here, wait for the box to load and then hover over the “Subscribed” link. Then uncheck the “Comments and likes” choice. I would rather my comments on friends’ posts not be made public. Thanks! Then repost if you don’t want your EVERY MOVE posted on the right for everyone to see.

Well, bad news: keeping your Facebook comments to yourself isn’t that easy, particularly when you’re commenting on someone else’s Facebook post.

That’s because whenever you comment directly on a friend’s Facebook story, you’re essentially at the mercy of their privacy settings.

For instance, if your pal’s Facebook post is publicly viewable, then everyone on Facebook will be able to read any comments on the post—including yours.

At the other end of the spectrum, if a friend—say, Bob—posted an update to just his friends and you commented on his update, only you, Bob, and Bob’s friends will be able to see your comment. That also means Fred won’t see your comment … assuming Fred isn’t a friend of Bob’s. (Confused yet?)

OK, but what if you follow the advice above and ask your friends to unsubscribe from your comments? Well, you certainly can, but keep in mind that your friends’ Facebook subscription settings apply only to them—that is, just because they unsubscribe from your comments doesn’t mean that other Facebook users can’t still see them. And of course, your friends can re-subscribe to your comments at any time.

So, what to do? Try this:

1. Check to see how your friends are sharing their posts before you comment on them. Look at the bottom of a given post, find the time stamp (such as, “8 hours ago”), and hover your mouse over the little icon immediately to the right.

If the icon looks like a globe and reads “Shared with: Public,” then any comments you leave will be publicly viewable, too. If the icon looks like a pair of little heads and reads “Shared with: Joe’s Friends” or “Shared with: Friends of friends,” you’ll know if the circle of sharing is smaller or larger.

2. Dying to comment on a shared link or photo, but uncomfortable with how many people your friend is sharing the post with? You can always click the “Share” button to the left of the time stamp, then post the story to your own wall using your own privacy settings; just don’t forget to select the setting you want from the drop-down menu in the top-right corner of the pop-up window.

3. Double-check your own privacy settings before you post. If you share a link or photo on your own profile, the default privacy setting is whatever the setting was for your last post.

In other words, if your last post was publicly viewable, all your subsequent posts will be too—and that means Bob will see Fred’s comments on your post, even if Bob and Fred aren’t Facebook friends.

Click here for details on how to check your current privacy setting for status updates.

4. Think of a friend’s Facebook post like a group conversation at a party; if you chime in with a comment, everyone else participating in the chat will hear it, too.

If that idea makes you uncomfortable, consider keeping your comments to yourself.

Does all this sound way too complicated? Well, you can always quit Facebook for good; here’s how.

Looking for more Facebook tips and how-tos? Click here!

Note: This updated and revised article was originally published in September 2011.