There's a reason why the #freethenipple campaign blew up on Instagram: the photo-sharing website is typically quick to pull down posts showing women's nipples, even if there's nothing pornographic about the photos. Why? Well, according to Business Insider, the app's cofounder puts the blame on Apple. Instagram CEO Kevyn Systrom explained his Facebook-owned company's side during a talk in London, claiming that its guidelines can't be changed due to Apple's age rating. Since IG wants to retain its current 12+ rating in order to have a wider audience -- only rated 17+ apps are allowed to feature explicit content -- it has to continue taking down posts that showcase nudity.