Thread:AnnabellRice/@comment-37854037-20191119141457/@comment-16461120-20191121223514

Bitly is essentially a redirect website. You can take any URL and run it through there to get a shorter URL unrelated to the original site, which is popular with sites like Twitter that limit characters in posts, but can be used to bypass another site's filters that block specific addresses, so that's why it's now being blocked too.