The ironic part is that many of the posts Facebook plans to scrub out became popular because users liked and shared them. In other words, it's in many cases the fault of users for promoting spammy content. While some might argue that the popularity of feed content should be up to the users, like on Reddit, that's never exactly how Facebook has operated. When spammy photos and too many invites from games appear inside more News Feeds, people engage less — even if those photos and invites were generated by your friends. Unfortunately for Facebook, people tend to blame Facebook for spam instead of the friends posting the actual spam — so the company is taking action.

อ้างอิง :
http://www.theverge.com/2014/4...s-who-ask-for-likes-and-shares 