When you like an article with Facebook, this fast is shared to your friend who will see "Jane Doe likes Hallo Hallo Mall." From this article in Forbes I learned that:
Facebook is now recycling users Likes and using them to promote “Related Posts” in the news feeds of the user’s friends. And one more thing, the users themselves have possibly never seen the story, liked the story or even know that it is being promoted in their name.
Basically, if you click the Like button for something once, it is license for Facebook to post Likes in your name for other posts from the same source. Even if you never Liked a particular post, or even if you never saw it. Basically, Facebook is now posting for you, without you knowing it.
I have a Facebook account I use to share things with friend, though I actually open it and check what is going on there anymore. Still, to be nice to my Facebook Friends I went to Profile Page, and edited my likes by removing them all. I decided I should be nice and not spam my Facebook Friend.