You might be onto something, I noticed that all the banned links were in the format: https://signal.me/#eu/fdy5h1miMifXa https://signal.me/#eu/fdy5h1miMifXa...

You might be onto something, I noticed that all the banned links were in the format: https://signal.me/#eu/fdy5h1miMifXa https://signal.me/#eu/fdy5h1miMifXa... The URL hash (the part after #) is often not considered by automated systems to be a part of URL that's meaningful, because hash is normally only used for addressing parts of the website that was loaded based on the previous part of the URL. If a particular Signal.me link was flagged for whatever legitimate reason (contained malware or illegal content) it's entirely reasonable that an automated system would strip the hash and block the whole domain (because the path part in this URL is just "/" and nothing else). It'll be interesting to see whether they address and reverse it. If not, then we can be fairly sure this was intentional.