http://petapixel.com/2015/02/24/google-and-reddit-tighten-their-policies-regarding-explicit-photos/
I suppose it had to happen sometime. People had long been abandoning their blogs on Blogger, or migrating them to Wordpress.
It might be partly the pornography community clamoring to the masses to stop infringing on their copyrights, sharing their "pay-for-play" content freely across the Internets. It might be partly just the users racking up immense amounts of bandwidth costs in sharing the content on these free services.
Either way, it's a "whoa boy" time for the Internet community, even though some like @cyberczar and the likes have long predicted this doom.