There is no mainstream browser that automatically directs the user to a list like /r/fullmoviesonyoutube. A browser is a generic tool that can be made to visit infringing content, but does not itself encourage the user to do so. If there really were no difference between Popcorn Time and a browser, nobody would have used Popcorn Time, because 100% of its users already had browsers.
What if Popcorn Time made the user click a button 100 times before granting full access? Is that enough effort? Or if a link was proposed 2 clicks away from the homepage of a major browser? Is that too little effort? Where do we draw the line? I guess we don't, since the DMCA's scope is so large.
If the primary purpose of the app were still infringement but you had to click a button 100 times to use the app, the primary purpose of the app would still be infringement.
