That’s a mastodon server. Firefish.social is admined by a single person I think. They probably just need to add that server to their blocklist. Like any federated app like Kbin and Lemmy this will need to be addressed, but is hardly the fault of Firefish the software. If anything like mastodon.social Firefish.social will need help moderating which servers to block as it grows.

The admin would absolutely not want this federating with Firefish.social. I am sure as soon as we let them know they will deal with this.