I'm curious why people link to a summary of an article that actually resides elsewhere--a similar example was just submitted at http://news.ycombinator.com/item

I'm curious why people link to a summary of an article that actually resides elsewhere--a similar example was just submitted at http://news.ycombinator.com/item?id=1568011 http://news.ycombinator.com/item?id=1568011. In both cases the summary bore a headline which significantly altered one's initial understanding of the article at hand, and in both cases it led to a more difficult and/or unrewarding read.