This is complicated and unreliable, and I don't think we should do it.

1. What's the "name" of the blocked website? We can't trust what the blocked for spam / abuse website says its name is, which is what Citoid will tell us -- there's going to be plenty of things on the list that'll have us saying things like "CNN is blocked" / "the White House press room is blocked" because they're impersonating a legitimate website, and that's just going to be confusing.

2. Showing the URL we blocked makes more sense since it's actually unambiguously representing the thing we're blocking, but it's also long and hard to read.

I.e. "this site" is better than trying to show the name in the message, since all it does is push the user to look more closely at the citation we generated, which contains all the information we have.

Note also that while most sites are blocked by domain, filters are regular expressions which run on the whole URL, and it is not trivial to work out which part of the URL triggered the block, for example:

https://books.google.co.uk/books?id=alllAwAAQBAJ&redir_esc=y&hl=en

is blocked by the pattern:
books.google.*?id\=alllAwAAQBAJ

We can't say
books.google.com is blocked
because that isn't true as we have only blocked this specific title, and we don't really want to say
books.google.*?id\=alllAwAAQBAJ is blocked
as that is far too technical.