How to block uploaders?

[Triramama]

I want to block one idiot who pours a lot of english dub webms on gelbooru, he is "user:15taylorn" when i type that in blacklist menu, the app just breaks and refuses to show any results, if i type just "15taylorn" nothing happens, what gives? How do i block files by one uploader specifically? if i use gelbooru's block feature on my account, the app shows his stuff anyway even if i log in from "sources", despite it not appearing on the web

[Bionus]

On Gelbooru, you could just use -user:USER_NAME since the website supports that format.

In Grabber, there is currently no way to filter by user name on Gelbooru, but there is a way to filter by user ID. To do so, you can blacklist (or post-filter) authorid:USER_ID. On some sources, you can also use author:USER_NAME but seems like it's not supported on Grabber's Gelbooru at the moment (so I'm marking this issue as an enhancement request).

Note that when blacklisting like this, I would recommend also putting the source's name in the blacklist, to not impact other sources: site:gelbooru.com authorid:USER_ID.