@Pootle,
You can't, unless you create a private, secret group, invite your friends to it, and do all your posting in there. Or you can tell every single one of your friends to tighten up their privacy settings, and that will never happen, amirite? Or you can command all of your friends to stop being friends with people who you don't want to see your activity (e. g. an ex, I am guessing). Yeah, that one's not gonna fly, either.
FB is not too great with privacy, and one of the reasons is because this action has three pieces to it:
- You hit like and it tells your friends only as a consequence of your privacy settings
- They hit like and it goes out to whoever is included in their privacy settings. If those settings are tight, then the sphere of people who see this activity is small. If not, then it is larger.
- Friends of your friends with looser privacy settings see their activity. And if they are interacting on the same content as you are, then these friends of friends will see your activity as well.
Solutions:
- Drop friends who are pals with someone you don't want them to be friends with. Not fun but it will break part of #2, above.
- Stop being friends with people who are friends of friends of people you don't like. A much more daunting proposition and nigh well impossible. Consider that a person with 10 friends who each have 5 friends is potentially broadcasting to 60 people (10 friends + 50 friends of friends), and then if the friends of friends are each pals with a unique additional 5 people apiece, then that figure exponentially rises to an added 250 people (5 x 50). Plus it's a lot of work to hunt out who is friends of your friends' friends. You think someone will just tell you this information? That's hardly plausible.
- Private secret group as I suggested, above.
- Like less stuff, or at least not the stuff that's what you want to keep private. Find another way to show your appreciation for it, such as by sending PMs. This is a lot more work.
- Make your peace with this and just plain deal with it. If the world knows you like Nickelback, live with it. Or
- Use Facebook less.
Your choice.