This seems a really dysfunctional way to implement a sort of f-lock

Tumblr has created a way to not show a Tumblr via the web URL but only on the dashboard to followers. But as I understand it, the behavior is that anyone can follow you if they know your name unless you explicitly block them. So content is not actually private as such, because if I for example came across one of these error pages following at a web URL, I could follow the name in the URL and then see the content on my dash, at least unless/until I got blocked.

Only I probably couldn't find any specific content because I'd have to scroll back through my dashboard to see it, since the URLs don't work anymore for anyone, logged in or not, including the owner even, based on the reblog comments?! So if you hide your Tumblr, how could you find or see your old posts if neither archive nor tag links work any longer?

And how does this behave with reblogging? The post says the social functions all work as before, including reblog, does that mean if your followers, who may not even realize you disabled URLs as there is no symbol on the posts like on LJ/DW, can still reblog and it would show on theirs with a proper URL (and be visible to all including search engines if they set their Tumblr for maximal exposure?) or only reblog through the dashboard feeds to their followers but not the public Tumblr?

This implementation of (faux-)privacy doesn't sound like a recipe for wanky misunderstandings and disaster at all... /sarcasm