FiftyThree response to Facebook's Paper(news.fiftythree.com)
news.fiftythree.com
FiftyThree response to Facebook's Paper
http://news.fiftythree.com/post/75486632209/every-story-has-a-name-fiftythrees-story-began
http://news.fiftythree.com/post/75486632209/every-story-has-a-name-fiftythrees-story-began
And even if you're thinking "trademark", in this case, the Paper apps in question have very different purposes.
No one should have a monopolistic right to use the word "Paper" (or in my opinion any word).