[1] https://www.ohchr.org/en/NewsEvents/Pages/DisplayNews.aspx?N...
That's a Bad Thing, for sure. But I suspect most of Assange's fans aren't upset about the treatment of Assange because they oppose the carceral state; it's because they're fans of Assange.
In other words, if you say "I'm opposed to the conditions of Assange's detention", I suspect you're not saying you oppose the normal conditions of legal detention--which perhaps you should--but, rather, that you are opposed to the fact that those norms we happily apply to millions are being applied to Assange.
https://www.theguardian.com/world/2019/may/10/dutch-court-bl...
From what I've found, the UK in particular is not in a huge position to throw stones given the standards of their prisons result in this being yet another area where they're a sort of mini-USA. But e.g. the Swedish system would be better.
Just saying this because you think it's necessary.