I don't see too big of a problem with it regardless. If you spend your time liking, sharing, or commenting on something there is obviously an 'emotional' response to it. As long as FB doesn't start saying 'your friend x' likes this, when in fact they posted a comment disagreeing there isn't a huge problem. Even then I think the fact that it created a response of some sort is a 'like', atleast in the sense people I see use the like button..
For most purposes, yes. But the author called out news reporting that quotes these "stats". Its important for journalists to understand the differences.
