I have heard that tumblr's automatic porn detection is currently based entirely on how much flesh tone color is in the picture or video. The posts that have been tagged NSFW seem to back that up. And since they're clamping down on adult content more and more — to the point that blogs marked with enough NSFW will be locked into only visible by logged-in users with safety settings off, I am fairly concerned that blogs will get shut off or shut down based entirely on idiocy. by foodffs via Tumblr