Defederation is the nuclear option. Until now we had removed any communities we weren't comfortable hosting, and treated users on a case-by-case basis based on how they behaved in our communities, which worked for a while but became untenable.
When we started this project the admin team felt that welcoming outsiders into our (wholesome, sane) Star Trek communities was the net-positive action. But as I said it became too much to handle so we unfortunately had to cut the cord.
The downvotes are all coming from accounts on other instances, which as @ValueSubtracted@startrek.website suggested, makes us think it's most likely people browsing "All" and not appreciating seeing twenty discussion posts (not that that justifies it).
Any slowness should be gone by now, I haven't seen the JSON thing happen to me yet, but I'll look into it. Next time it happens to you can you DM me a screenshot?
We've been targeted too by what's probably a couple of script kiddies trying to brute force their way into our server. Not exactly a DDOS but a similar effect. Just had to remodulate the shields a few times.
Stories like this make me very happy to hear. When I heard the /r/StarTrek and Daystrom mods talking about joining Lemmy I'd thought bringing their reputation for positivity and tolerance to a Trek-themed instance could provide a familiar and comfortable jumping-off point for users unsure about the broader Fediverse.