At a personal inbox level, yes block as many npubs as you want, and optionally don't be notified when/if they mention you. But @fiatjaf likely misspoke, when typing: "block them from mentioning".?

But, the bridge WAY TOO FAR is blocking comments in the note's comment thread, as other users see it. These users have the ability to create an individual block list for themselves.

Imagine if White House Gov or pharmacy companies had the ability to censor descent at this level. The easy next logical step is an approved repliers list. This would be safe and effective, after all.

This is exactly how you Mastodon my Nostr, even if the sky is blue.