Tumblr got rid of the porn for the same reason most general websites get out of porn. Good guys in government law enforcement and intelligence agencies were intensely scrutinizing them. The operators freaked because they were being made aware that their attempts to mask every type of criminal communication from organized crime to international terrorist organizations wasn't working anymore, so they scuttle their porn haven which kills the insane level of bandwidth traffic that would mask the criminal communications.
Which begs we ask the question. If no one is paying out of pocket to use their sites, who is footing the dough to keep them operating?
(post is archived)