![](/static/253f0d9b/assets/icons/icon-96x96.png)
![](https://lemmy.dbzer0.com/pictrs/image/a18b0c69-23c9-4b2a-b8e0-3aca0172390d.png)
I suppose you could argue an “illegal number” is: https://en.wikipedia.org/wiki/Illegal_number.
For example, the HD DVD encryption key saga was originally fought via DMCA notices to Digg: https://en.wikipedia.org/wiki/AACS_encryption_key_controversy
Works for me with Lemmy-UI. I’m guessing whatever client/browser you’re using is including the period at the end of the sentence in the URL.