I can understand why someone would be confused about that but I’m not really sure whether a frequent user of Facebook would be.

I have never ‘liked’ anything and as such never experienced the consequences of doing so. I figured that because of the placement of like buttons on websites (in the sidebar or below articles, often next to digg or reddit buttons) clicks on the ‘like’ button are akin to upvotes. I’m not at all a frequent user of Facebook, that’s why I’m not sure how widespread that perception is among frequent users.

I never read anything in my Facebook stream (or however that is called) anyway, so I couldn’t care less.